A Workshop on

Current Trends in Near Infrared Astronomy in India

Jointly Organised by

Tata Institute of Fundamental Research (TIFR),

Mumbai

The Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune

Indian Institute of Astrophysics (IIA),

Bengaluru

November 25 – 27, 2014

Abstract Book

Venue: TIFR Balloon Facility, Hyderabad, India. http://www.tifr.res.in/~nirworkshop/

A Workshop on

Current Trends in Near Infrared Astronomy in India

Scientific Programme

Tuesday, November 25, 2014

8:30 – 9:45 Registration

9:45 – 10:00 Introduction, Welcome, Inauguration 10:00 – 10:30 Near Infrared Astronomy in India B. G. Anandarao 10:30 – 11:00 HIGH TEA

Session 1 : Star Formation and Interstellar Medium (Chairperson: S. K. Ghosh)

11:00 – 11:25 Triggered Star Formation Anil Pandey

11:25 – 11:50 Understanding the Role of Filaments in Star and Cluster Formation Manash Samal

11:50 – 12:15 An Infrared Insight into Dense Cores in Massive Star Formation Sarita Vig

12:15 – 12:40 Astrochemistry in the Optical – Near Infrared Wavelengths Bhaswati Mookerjea

12:40 – 14:00 Lunch Break and Poster Session

Session 2 : Star Formation and Interstellar Medium (Chairperson: Anandmayee Tej)

14:00 – 14:25 Near Infrared Spectroscopic Studies of Protostars and Protoplanetary Disks Manoj Puravankara

14:25 – 14:45 FU Ori Type Outburst Sources in Young Low Mass Stars Joe Philip Ninan

14:45 – 15:05 Optical Spectroscopy of X-ray Sources in the Carina Nebula Kaushar Vaidya

15:05 – 15:25 Star Formation in NGC 3293 Priya Hasan

15:25 – 15:45 Deciphering stellar clusters and their associated properties through deep NIR data Kshitiz Mallick

15:45 – 16:15 Tea / Coffee Break

Session 3: Interstellar and Circumstellar Dust, Lunar Occultation Technique (Chairperson: Bhaswati Mookerjea)

16:15 – 16:40 Circumstellar Dust Models for NIR Spectra of IRAS Objects Ranjan Gupta

16:40 – 17:05 Star Formation in Dark Clouds and the Role of NIR Polarimetry Asoke K. Sen

17:05 – 17:25 Spatial Asymmetry Detected in UZ Arietis using Lunar Occultation Tapas Baug

19:00 Workshop Banquet (Aalankrita Resort)

Wednesday, November 26, 2014

Session 4 : Late Type Stars, Extra-Solar Planets, Brown Dwarfs (Chairperson: Ranjan Gupta)

9:45 – 10:10 On the Distance Scale using NIR Period – Luminosity Relations for Cepheids H. P. Singh

10:10 – 10:30 Photometric Variability in Ultra-cool Dwarfs: Understanding of Evolving Weather Patterns Soumen Mondal

10:30 – 10:50 Low Mass Eclipsing Binaries Priyanka Chaturvedi

10:50 – 11:15 Optical and Near Infrared Spectro-polarimetry of Brown Dwarfs and Exoplanets Sujan Sengupta

11:15 – 11:45 Tea / Coffee Break

Session 5 : AGN, QSOs (Chairperson: G. C. Anupama)

11:45 – 12:05 On the Nature of Weak Emission Line Radio-Quiet Quasars Hum Chand

12:05 – 12:30 Physical processes in AGN: A multi-wavelength perspective C. S. Stalin

12:30 – 13:45 Lunch Break and Poster Session

Session 6 : Novae and Supernovae (Chairperson: U. S. Kamath)

13:45 – 14:05 Near Infrared Studies of Novae R. K. Das

14:05 – 14:25 Observing the Shock Wave during 2014 Outburst of Recurrent Nova v745 Sco Vishal Joshi

14:25 – 14:50 Near Infrared Properties of Supernovae D. K. Sahu

14:50 - 15:10 Optical and NIR Observations of SN 2014J Shubham Srivastav

15:10 – 15:30 Tea / Coffee Break

Session 7 : Existing Instrumentation (Chairperson: A. N. Ramaprakash)

15:30 – 15:55 TIFR Near Infrared Spectrometer and Imager (TIRSPEC) D. K. Ojha

15:55 – 16:20 PRL Near Infrared Camera / Spectrometer – Performance and First Results N. M. Ashok

16:20 – 16:45 Hanle Echelle Spectrograph (HESP) and possible synergy with TIRSPEC T. Sivarani

16:45 – 17:10 Near Infrared Astronomical Instrumentation in Japan N. Kobayashi

17:10 – 18:00 Visits to Labs and Balloon Production Facility

18:00 – 19:30 Practical Session for Students (NIR Spectroscopic Data Reduction)

19:30 Dinner

Thursday, November 27, 2014

Session 8 : Future Instrumentation (Chairperson: B. G. Anandarao)

9:15 – 9:30 Mid-IR Imager for HCT U. S. Kamath 9:30 – 9:50 TANSPEC: TIFR-ARIES Near Infrared

Spectrograph Saurabh

9:50 - 10:15 Planned Near-IR Instruments for the Thirty Metre Telescope A. N. Ramaprakash

10:15 – 10:40 A Brief Overview of TMT Science Cases G. C. Anupama

10:40 – 11:00 Wavelength Calibration for Optical and NIR Astronomy R. K. Banyal

11:00 – 11:15 Tea / Coffee Break

Session 9 : Future Instrumentation (Chairperson: A. K. Pandey)

11:15 – 11:40 Infrared Spectroscopic Imaging Survey (IRSIS) experiment S. K. Ghosh

11:40 – 12:05 3.6m aperture Devasthal Optical Telescope M. Gopinathan

12:05 – 12:30 The PRL 2.5m Telescope Abhijit Chakraborty

12:30 – 12:45 Workshop Summary

12:45 – 14:00 Lunch Break

14:00 – 16:30 Practical Session for Students (NIR Spectroscopic Data Reduction)

16:30 Tea / Coffee Break

19:30 Dinner

Poster Presentations

Poster No. Title Author

1 Near Infrared study of Barred Dark matter dominated galaxies using TIRSPEC observations Honey M.

2 Characterising protostellar evolution with infrared spectroscopy Debdutta Paul

3 Magnetic field geometry in LDN 328 Archana Soam

4 Fourier decomposition of Cepheid light curves at optical, near-infrared and mid-infrared wavelengths Anupam Bhardwaj

5 Preliminary optical design of Wi-Fi Pol (Wide Field Polarimeter) for 1.3m Telescope Neha Sharma

6 High-mass star formation towards the Infrared Bubble S10 Swagat Ranjan Das

7 Infrared and Radio Investigation of the Cometary HII Region IRAS 17256-3631 Veena V. S.

8 CLOUDY modelling of Recurrent Nova RS Ophiuchi, 2006 outburst Anindita Mondal

9 Deep near-infrared survey of the stellar content and star formation in Sh2-311 region Ram Kesh Yadav

10 Classification of brown dwarfs using near infrared photometry & spectroscopy Govind Nandakumar

11 Radio & Infrared study of star forming region 20286+4105 Varsha Ramachandran

12 Study of morphology and stellar content of the Galactic HII region IRAS 16148-5011 Kshitiz Mallick

13 The young cluster NGC 2282 : a multi-wavelength perspective Somnath Dutta

14 Star Formation Activity in the IRAS 22308+5812 region Tapas Baug

15 J, H, and K band study of Contact binaries Kandulapati Sriram

16 Identification of UV stellar point sources using NIR colour cut method

Ananta Charan Pradhan

17 Design and Development of IR Camera for Robo-AO, P-60 Telescope, Caltech Jyotirmay Paul

18 Structural analysis of near infrared galaxy NGC 3115 Dhanya Joseph

19 Phase dependent spectro-photometric studies of a new Mira variable MASTER Optical Transient J212444.87+321738.3

Supriyo Ghosh

20 Multi-wavelength Radiometer Observation of Aerosol Properties and its Radiative Impact over Hyderabad, India

P. R. Sinha

ABSTRACTS Near-Infrared Astronomy in India

B.G. Anandarao Physical Research Laboratory, Ahmedabad-380009

November 25, 2014, 10:00 hrs.

The installation of the first ground-based Infrared Observatory at Mt. Abu heralded the beginning of Near-Infrared Astronomy in India, some three decades ago. The near-infrared region is one in which a number of spectral diagnostics occur, such as atomic, molecular and dust/ice features which help in probing the prevailing physical conditions in a number of astrophysical sources. In particular, sources that are enshrouded by dust and gas suffer large extinction of visible light and hence the infrared astronomy is the best way to probe them. We discuss here the early years of infrared astronomy in India and its subsequent growth and interest till date. We briefly review the scientific work done in India in the fields of star formation, evolution of intermediate mass stars (AGB/Post-AGB stars) and transient phenomena in certain binary systems such as Novae. We bring out the significance of the scientific contributions from modest-sized telescope(s). We highlight the importance of multi-wavelength approach in some of these studies. Finally, we indicate some future programmes that are being planned, in view of various forthcoming national and international facilities.

Session 1 : Star Formation and Interstellar Medium Triggered Star Formation

Anil Pandey ARIES, Nainital

November 25, 2014, 11:00 hrs.

It is now well established that massive stars in star forming regions can trigger next generation of star formation. Theoretical simulations suggest two main processes for triggered star formation; the radiation driven implosion (RDI) process and collect & collapse (CC) process. In this talk I will discuss observational aspects of triggered star formation scenario. The young stellar objects (YSOs) in star forming regions have been identified using the near-infrared (NIR) and mid-infrared (MIR) observations. The age of the identified YSOs was estimated using the optical color-magnitude diagram. The age of YSOs, the morphology of the regions and the global distribution of YSOs indicate that the star formation can be triggered by either (RDI/ CC) of the processes.

Understanding the Role of Filaments in Star and Cluster

Formation Manash Samal

LAM, France

November 25, 2014, 11:25 hrs.

Recent observations of molecular clouds reveal a complex structure, with gas and dust often arranged in filamentary, rather than spherical geometries. The association of cores and young protostars with the filaments suggests a direct link with the process of star formation. In this talk, I shall discuss physical conditions, morphologies, and kinematics of interstellar filaments and their relationship with star and/or cluster formation.

An Infrared Insight into Dense Cores in Massive Star Formation Sarita Vig

IIST, Trivandrum

November 25, 2014, 11:50 hrs.

It is a fact well-acknowledged that massive stars form in clustered environments. The development of a young cluster depends sensitively on events that occur when it is still embedded in the core from which it formed. The study of young embedded clusters through near and mid-infrared observations provides vital clues to star-formation history such as disk-fraction, age and initial mass function. I will present few examples of such young, optically-obscured embedded clusters in massive star forming regions. In addition, I will briefly discuss how these observational results can be used along with simulations to gain an insight into the star formation history.

Astrochemistry in the Optical – Near Infrared Wavelengths Bhaswati Mookerjea

TIFR, Mumbai

November 25, 2014, 12:15 hrs.

I will (a) review the optical and near-infrared observations which have contributed to the study of chemistry of the diffuse and dense interstellar medium and (b) identify areas in astro-chemistry which can be addressed with the upcoming Indian instrumentation endeavours.

Session 2 : Star Formation and Interstellar Medium

Near Infrared Spectroscopic Studies of Protostars and

Protoplanetary Disks Manoj Puravankara

TIFR, Mumbai

November 25, 2014, 14:00 hrs.

Mass accretion from circumstellar disks surrounding young stellar objects plays a crucial role in the formation of stars and planetary systems. In the early embedded phase, mass accretes from the molecular cloud core onto a protostar, through an accretion disk, and it is during this phase that the initial masses of stars and the initial conditions for planet formation are set. Disk accretion also controls and regulates planet formation and the eventual dissipation of protoplanetary disks. Measurements of disk accretion rates and characterisation of its evolution in young stars are two critically important inputs for a comprehensive theory of star and planet formation. Many of the observational tracers of accretion fall in the near-IR wavelength range, making NIR spectroscopy a powerful tool to study disk accretion in young stars. In this talk, I will provide a brief overview of our current understanding of the role of disk accretion in star and planet formation and discuss our efforts to measure accretion rates in protostars and protoplanetary disks.

FU Ori Type Outburst Sources in Young Low Mass Stars Joe Philip Ninan

TIFR, Mumbai

November 25, 2014, 14:25 hrs.

Accretion in low mass young stellar objects is found to be episodic in nature. They undergo short duration, sudden increase in accretion rate by a factor of 10 to 100. These outbursts are classified as FUors (stronger outbursts, lasting many decades) and EXors (smaller outbursts, lasting few years). They typically show a sudden increase in brightness by ~5 mag in optical bands. These short timescale outbursts can explain many issues in low mass star formation like the "Luminosity problem". They have been observationally found to influence the silicate crystallization and other disc chemistry, which could play a crucial role in planet and comet formation. Due to their short timescale these events are very rare, and we have to deduce the physics behind the phenomena from a dozen sources discovered so far. We would like to present our long term observations of a peculiar source V899 Mon (IRAS06068-0641), first discovered by CRTS survey, which is still undergoing outbursts. From our optical and near-infrared photometry and spectroscopic observations, this object seems to be having properties of both FUors and EXors, similar to another famous source V1647 Ori (McNeil's Nebula Object). The outburst which started in 2004 underwent a sudden dimming during March 2011, and now it is back to its outburst phase. It showed an increased outflow and magnetic activity just before it went to quiescent phase in 2011. We present our results from the study of this object and its implication on models of FUors phenomena.

Optical Spectroscopy of X-ray Sources in the Carina Nebula Kaushar Vaidya

BITS, Pilani

November 25, 2014, 14:45 hrs.

The Carina Nebula is a highly active, massive star-forming region of our Galaxy, harbouring 70 O stars and some 200 OB stars. Owing to its extremely rich massive stellar content, relatively close distance of 2.3 kpc, and ongoing star-formation, this region offers a great opportunity to study star-formation, feedback of extremely massive stars on star-formation, and the physics of massive stars. We had identified about a dozen massive star candidates and over one thousand low-mass pre-main sequence star candidates using the X-ray and near-infrared observations of the two central clusters Trumpler 16 and Trumpler 14 of the Nebula. Here, we present the result of optical spectroscopy of a representative sample of massive and low-mass pre-main sequence candidates. In particular, we have found a new O star, and 7 B1-B2 stars, adding to the previously known OB stars of Trumpler 16 by 25%. We also detected 7 T Tauri candidates in addition to 3 mid-B and 5 Ae stars.

Star Formation in NGC 3293 Priya Hasan

MJCET, Hyderabad

November 25, 2014, 15:05 hrs.

NGC 3293 is a moderately young open cluster with an age spread of 20 million years where the lower mass stars seem to have formed first. We find the variation of the mass function in the core, inner and outer halo regions of the cluster and find that the high mass stars are concentrated at the core, but the low mass stars seem to be missing in the inner and outer halos, though the age of the cluster is much lesser than the period for dynamical evolution. Combining ALLWISE and 2MASS data, we classify the YSOs and trace the progress of star formation in the cluster. The clustering properties of Class I and Class II stars using the nearest neighbour technique are studied and we also trace the progress of star formation. We use the study to put constraints on coeval star formation and the IMF in the cluster.

Deciphering stellar clusters and their associated properties

through deep NIR data Kshitiz Mallick

TIFR, Mumbai

November 25, 2014, 15:25 hrs.

In this talk, we present the young stellar clusters - W40 and NGC 7538 - studied using deep NIR data from 3.8 m (UKIRT) and 8.2 m (Subaru) telescopes, respectively. The deep NIR data provides unprecedented detail of the stellar morphology, with detections reaching upto the brown-dwarf regime using the Subaru telescope. Complemented with multi-wavelength data, the star-formation and diagnostic tools such as the mass-function, luminosity-function can be much better understood and constrained.

Session 3: Interstellar and Circumstellar Dust,

Lunar Occultation Technique

Circumstellar Dust Models for NIR Spectra of IRAS Objects Ranjan Gupta

IUCAA, Pune

November 25, 2014, 16:15 hrs.

We calculate the absorption cross section of the composite grain models, consisting of host spheroidal silicates and inclusions of graphite. We study the absorption as a function of volume fraction of the inclusions, in the IR spectral range 5-25 microns. Further, we study the absorption efficiencies of dust grains with the porosities of the spheroidal silicate grains. To obtain the absorption efficiencies, we use the Discrete Dipole Approximation (DDA) as a tool to study the light scattering properties of dust grains. Using the absorption efficiencies of the composite grains and the porous silicate grains, we calculate the infrared fluxes at various dust temperatures, and compare the model IR emission curves with the observed IR emission from the circumstellar dust around seven hundred stars selected from the IRAS database. The composite spheroidal grain models with the axial ratio taking values between 1.33 and 2.00, and volume fraction, f, lying between 0.1 and 0.3, fit the observed IR fluxes from the circumstellar dust around the sampled IRAS stars reasonably well, giving the dust temperature between 270K and 300K, and 300 and 370K respectively for the composite grains with the graphite inclusions and the porous silicate grains. The Flux Ratio R = F(18 µm) / F(10 µm) is in the range of 0.10-0.20. Star Formation in Dark Clouds and the Role of NIR Polarimetry

Asoke K. Sen Assam University, Silchar

November 25, 2014, 16:40 hrs.

The polarimetry in the optical is believed to be a good tracer of magnetic field in star forming dark clouds, where the background star light gets polarized by the dichroic grains present in the cloud. However, the extinction of the background starlight and the corresponding polarization are often found to be uncorrelated. This could be due to the fact that, the polarization and the extinction are caused by two independent sets of dust grains or the ambient magnetic field in the cloud is unable to influence the background star polarization. The astronomers sometimes probe these clouds in NIR polarimetry, where it is understood that the polarization in the optical and NIR regions are caused by two different mechanisms. In optical, the polarization is caused by the dichroic grains in absorption and in NIR, the polarization is caused by the same grains due to thermal re-emission. The optical data can only trace the field orientation in the low-density edge regions of clouds, because, if the extinction is too high then no optical emission is transmitted. The NIR data can only trace the field orientation in the high-density central regions of the clouds, because

current NIR polarimeters are only sensitive to high column densities. However, the directions of magnetic field as estimated by these mechanisms are expected to be related and sometimes authenticate each other. Since the magnetic field plays a key role in star formation dynamics, it is very much necessary that we understand the processes causing NIR polarization together with the processes causing optical polarization and extinction in such star forming clouds.

Spatial Asymmetry Detected in UZ Arietis using

Lunar Occultation Tapas Baug

TIFR, Mumbai

November 25, 2014, 17:05 hrs.

Lunar occultation technique provides a novel opportunity to achieve angular resolution of 1 milli-arcsecond on the occulted source even with 1-m class ground-based telescopes. This high angular resolution is achieved because the diffraction fringes are produced by airless moon, far outside the earth's atmosphere, and the telescope serves here as light collector. However, it is a rapid event and observations require high speed photometry for proper recording of the occultation light curves. A specially devised sub-array operational mode of NICMOS IR-camera attached to 1.2m Mt Abu telescope is being used to record lunar occultation light curves. The main drawback of this technique is that we are bound to observe the sources situated at the lunar path and a single event gives one dimensional scan of the source. We have performed a detailed study on semi-regular variable, UZ Arietis, using three-epoch lunar occultation observations at 2.2 micron. Three well resolved uniform disk angular diameters are obtained at three different position angles across the source. Optical polarization observations are also performed from Mt Abu. Our lunar occultation measurements along with the polarization observations suggest a small asymmetry in the brightness profile of the source directed close to the polarization axis.

Session 4 : Late Type Stars, Extra-Solar Planets,

Brown Dwarfs

On the Distance Scale using NIR Period – Luminosity Relations

for Cepheids

H. P. Singh University of Delhi

November 26, 2014, 9:45 hrs.

We calibrate the near-infrared (JHK) period-luminosity (PL) and period-Wesenheit (PW) relations for the Galactic Cepheids using Light Curve Data and the distances. We use these newly calibrated PL relations together with NIR data for Cepheids in LMC and M31 to find the distances to LMC and M31. Photometric Variability in Ultra-cool Dwarfs: Understanding of

Evolving Weather Patterns Soumen Mondal SNBNCBS, Kolkata

November 26, 2014, 10:10 hrs.

The combination of condensate clouds and rapid rotation has long motivated searches for weather phenomena in Ultra-Cool (late-M, L and T) Dwarf (UCD) atmospheres. Photometric variability studies of UCDs are an important tool to probe the physical nature of their atmospheres. Photometric variability in these dwarfs are generally attributed to the presence of magnetic spots, or dust clouds. Surface features such as magnetic spots or dust clouds may cause optical/IR modulation as the object rotates, and possible to measure the period of rotation of a dwarf. These dwarfs being rapid rotators, the photometric variability is observed within few nights of photometric monitoring using small to moderate-sized telescopes. Another characteristic of photometric variability in these class of objects shows lack of stability in both periodicity and amplitude, which might be due to evolving weather patterns. Few brown dwarfs are monitored using 1m class telescopes to understand their evolving weather patterns and understanding of their orbital nature, which will be discussed in this talk.

Low Mass Eclipsing Binaries Priyanka Chaturvedi

PRL, Ahmedabad

November 26, 2014, 10:30 hrs.

Despite a large number of low mass stars present in our galaxy, masses and radii for these stars are still not determined at higher accuracies due to their fainter magnitudes in visible band. Radii for stars less massive than Sun are known to be 10% smaller theoretically than observed and temperatures are 5% higher. These stars can be studied as companions to brighter primaries in single-lined eclipsing binary systems. With the Physical Research Laboratory Advanced Radial-velocity Abu-sky Search (PARAS) working at a resolution (R) of 67000, coupled with the PRL 1.2m telescope, Mt Abu, we have discovered few such systems which have M dwarfs as secondaries. I will be presenting RV and photometry results for object HD 213597 having 0.28 Msun M dwarf as secondary at a period of 2.4238 days. Other is SAO 106989 which is an F7 (1.2 Msun) type primary star and a mid M dwarf (0.3 Msun) with a period of 4.39 days. The last system is HD 23765 which is also a F-type main sequence star having a 0.4 Msun M dwarf orbiting at a period of 1.68 days. Similar systems discovered will make the sample of M dwarfs statistically significant. Optical and Near Infrared Spectro-polarimetry of Brown Dwarfs

and Exoplanets Sujan Sengupta

IIA, Bengaluru

November 26, 2014, 10:50 hrs.

Brown dwarfs inhabit the realm intermediate to the least massive stars and giant planets. They are born like a star but fail to sustain nuclear burning inside their core. Consequently they could not become a star. The atmospheres of brown dwarfs are very much similar to the hot giant planets. Therefore, understanding the atmosphere of brown dwarfs provides important insight onto the atmosphere of giant extra-solar planets. Depending on their spectra, brown dwarfs are divided into three classes - L, T and Y dwarfs. The relatively hotter brown dwarfs belong to the subclass of L dwarfs. Due to incomplete gravitational settling, the atmosphere of L dwarfs should contain condensates mainly of silicate. The indirect evidence for the presence of dust cloud in the atmosphere of L dwarfs comes from the diagnosis of its optical and infra-red spectra. The direct evidence of dust comes from the detection of linear polarization in the optical as well as near infrared bands. The atmosphere of the directly imaged, hot and young giant exoplanets resembles that of L dwarfs owing to comparatively lower surface gravity. In the present lecture, I shall discuss the physical and chemical properties of the atmosphere of L brown dwarfs as well as the directly imaged exoplanets which are derived from the detailed theoretical analysis of the observed spectra as well as the observed photo-polarimetric data.

Session 5 : AGN, QSOs On the Nature of Weak Emission Line Radio-Quiet Quasars

Hum Chand ARIES, Nainital

November 26, 2014, 11:45 hrs.

Until recently, weak emission line feature (EW < 15A) in AGN holds only for its subclass called blazar, however large optical survey such as SDSS has resulted in few dozens of radio-quiet weak emission lines QSOs (RQWLQs). The reason for the abnormally weak emission lines in RQWLQs is yet to be fully understood. One possibility is that they may be the radio-quiet counter part of Bl Lac Objects, as a result they may show distinctly larger variability, for which we have recently started a monitoring program using ARIES 1.3m telescope. Among other possibilities, the explanation by model consisting of small covering factor of the broad line region (BLR) is quite prominent, which has additional consequence observable in the infrared (IR) band. This is due to the fact that covering factors of the BLR and of the dusty torus have to be the same, and hence small BLR of WLQs can cause an evaporation of dust in the torus and a reduction of its IR emissivity. We are investigating such scenarios, by modeling the SED of WLQs based on IR photometric observation in J, H and K band using TIRSPEC at HCT, and compare them with that of the composite SED of normal QSOs. In this talk, we will discuss our preliminary results based on IR, along with results from our extensive optical monitoring program of WLQSOs over the last two years.

Physical processes in AGN: A multi-wavelength perspective C. S. Stalin

IIA, Bengaluru

November 26, 2014, 12:05 hrs.

Flux variability was established as a characteristics feature of active galactic nuclei (AGN) soon after their discovery. This particular property of AGN can be used effectively as a tool to understand the physical processes happening in the central regions of AGN. With the availability of multi-wavelength light curves it has now become possible to probe the connection between different emission regions around the central engine. Modelling of the broad band spectral energy distribution of AGN using near-simultaneous multiband observations spanning over a wide range of wavelengths from low frequency radio waves to high energy gamma-ray in the recent past has led to a better understanding of the various emission processes in these sources. Recent results on multi-band observations of few AGN will be discussed.

Session 6 : Novae and Supernovae Near Infrared Studies of Novae

R. K. Das SNBNCBS, Kolkata

November 26, 2014, 13:45 hrs.

The novae outbursts occur due to thermo-nuclear-runaway in a degenerate layer on white dwarf (WD) surface that is formed by continuous accretion of hydrogen-rich matter by the WD from the secondary companion star through an accretion disk. As a consequence of the explosion tremendous amount of energy is emitted almost over the entire electromagnetic wavelength region. Out of these, Infrared (IR) observations have played an important role in understanding different aspects of the phenomena, for example, how classical novae participate in the chemical evolution of the Galaxy, how infrared observations, combined with optical measurements, can provide quantitative measurements of the primary physical parameters that characterize the outburst, the abundances of elements that are present in the ejecta, the properties of the grains that condense in the nova wind etc. In this talk different observational aspects of classical and recurrent novae outbursts, in the near-IR band (1-2.5 micron) will be discussed and important results will be reviewed.

Observing the Shock Wave during 2014 Outburst of Recurrent

Nova v745 Sco Vishal Joshi IUCAA, Pune

November 26, 2014, 14:05 hrs.

V745 Scorpii underwent the third known outburst of recurrent nova on 2014 February 6. It is the latest nova, apart from five other known novae, to show gamma-ray emission. We observed the outburst in near-infrared almost on a daily basis starting from 1.3 d after the outburst. Our analysis shows the formation of the shock wave by high velocity (~4000 km/s) nova ejecta decelerating into its surrounding environment. The shocked gas is heated to a very high temperature exceeding 108 K immediately after outburst commencement. The shock does not show a free-expansion stage but rather shows a decelerative Sedov-Taylor phase from the beginning. Such strong shock fronts are known to be sites for Gamma-ray generation. It may be an important test bed to resolve the crucial question of whether or not all novae are generically gamma-ray emitters by virtue of having a circum-binary reservoir of material that is shocked by the ejecta rather than gamma-ray generation being restricted to only symbiotic systems with a shocked red giant (RG) wind. Our analysis also suggests that the WD in V745 Sco is very massive and a potential progenitor for a future SN Ia explosion.

Near Infrared Properties of Supernovae D. K. Sahu

IIA, Bengaluru

November 26, 2014, 14:25 hrs.

The photometric and spectroscopic properties of supernovae in the near-infrared region will be discussed. The NIR photometric data have confirmed that normal supernovae Ia are excellent standard candles, in contrast to optical wavelengths where they can only be used as standardizable candles. The NIR spectroscopic observations of type Ia supernovae provide several key diagnostics of SN Ia physics and help in understanding the explosion mechanism and the progenitor systems. The NIR studies of core-collapse supernovae resulted in improvement of estimates of the physical parameters such as bolometric flux, temperature and secured line identification. Along-with optical, the NIR data traces thermal emission from dust grains in core-collapse supernovae.

Optical and NIR Observations of SN 2014J Shubham Srivastav

IIA, Bengaluru

November 26, 2014, 14:50 hrs.

We present optical and NIR observations of the type Ia supernova SN 2014J, hosted by the nearby galaxy M82. The photospheric velocity near the epoch of B-band maximum, deduced using the Si II 6355 feature is ~12000 km/sec, which is at the border of spectroscopically normal and High Velocity (HV) SNe Ia. NIR spectra obtained near B-band maximum show broad features due to Mg II near 1.1 microns and Si II/ Mg II blend near 1.6 micron. The spectra, along with the bolometric light curve constructed using broadband magnitudes spanning UV to NIR, suggest that SN 2014J is essentially a normal, albeit a highly reddened type Ia supernova, with a decline rate parameter of ∆m15 ~1.1 in the B-band.

Session 7 : Existing Instrumentation

TIFR Near Infrared Spectrometer and Imager (TIRSPEC)

D. K. Ojha TIFR, Mumbai

November 26, 2014, 15:30 hrs.

The Infrared Astronomy Group of the Department of Astronomy & Astrophysics, TIFR, Mumbai has developed a near infrared (NIR) spectrometer and imager (TIRSPEC) in collaboration with MKIR, Hawaii (USA), based on 1024 x 1024 HgCdTe focal plane array (HAWAII-I 1K PACE detector; spectral response 1 - 2.5 microns), optimized for the 2-meter Himalayan Chandra Telescope (HCT) at Hanle. The TIRSPEC has a resolving power of ~1200 in J, H and K NIR bands and can be used effectively for various studies of Galactic and extra-galactic astrophysical problems in these bands with the 2-meter HCT. The TIRSPEC was installed on the HCT on June 20, 2013 for the first light and was thrown open for use by all astronomers from May 1, 2014. TIRCAM2 (TIFR near infrared imaging camera-II) is a closed cycle cooled imager that has been developed in-house by the Infrared Astronomy Group for observations in the NIR band of 1 to 3.7 microns with existing Indian telescopes. The main highlight is the camera's capability of observing in the nbL (3.59 microns) band, enabling our primary motivation of mapping of Polycyclic Aromatic Hydrocarbon (PAH) emission at 3.3 microns. The TIRCAM2 is presently being used with IUCAA's 2-meter Girawali observatory telescope near Pune. In this talk I will present the current status of TIRSPEC and TIRCAM2.

PRL Near Infrared Camera / Spectrometer – Performance and

First Results N. M. Ashok

PRL, Ahmedabad

November 26, 2014, 15:55 hrs.

A new near-infrared camera/spectrograph has been commissioned at the 1.2m telescope of Mt. Abu Infrared Observatory operated by Physical Research Laboratory. The design considerations, laboratory calibration and performance on the 1.2m telescope will be discussed. Representative science results from this instrument during the period 2013 December to 2014 June will be presented. The continuous spectral coverage from 0.87 to 2.5 micrometers has shown occasional spells of very high transparency in the spectral regions between the JHK atmospheric windows.

Hanle Echelle Spectrograph (HESP) and possible synergy with

TIRSPEC T. Sivarani

IIA, Bengaluru

November 26, 2014, 16:20 hrs.

Hanle Echelle spectrograph is a high resolution optical spectrograph for 2m Himalayan Chandra Telescope (HCT). It is currently being integrated and is expected to be commissioned during summer 2015. There are several modes of observations with sliced and unsliced fibers, that provides a spectral resolution R=60000, 30000 and a precise RV mode with an accuracy of 20 m/s. The spectrograph covers the entire optical wavelengths (350-1000nm), in a single exposure, which is unique among many spectrographs. The high altitude of Hanle, would be ideal for reaching blue end of optical. HESP will be used for studying abundances of most of the key elements of stellar nucleosynthesis, stellar pulsation and to detect jupiters and brown dwarfs. In this talk we discuss the science that can be done using HESP and possible areas of synergy in the NIR region using TIRSPEC.

Near Infrared Astronomical Instrumentation in Japan N. Kobayashi

Institute of Astronomy, Univ. of Tokyo, Mitaka, Japan

November 26, 2014, 16:45 hrs.

Japanese infrared astronomy started 50 years ago with a ground-based near-infrared observation of the Moon. Since then, NIR instrumentation activities have steadily grown at Kyoto University for more than 30 years by pursuing infrared astronomy with their own instruments attached to the telescopes at Mauna Kea Observatories in Hawaii. The instrumentation capability reached its maximum by building a variety of NIR instruments for the Subaru 8.2 m telescope. Now cutting-edge instruments, such as fiber-fed multi-object spectrograph and high-resolution spectrograph, have been developed not only for Subaru but also for many other telescopes. I will pick up several representative instruments to introduce some unique technical features as well as scientific results. Towards the end, I will try to discuss future directions based on past experiences of the community.

Session 8 : Future Instrumentation Mid-IR Imager for HCT

U. S. Kamath IIA, Bengaluru

November 27, 2014, 9:15 hrs.

In this talk I shall discuss about a Mid-IR imager proposed for the 2m HCT. This idea is in its very early stages, so a conceptual overview will be given.

TANSPEC: TIFR-ARIES Near Infrared Spectrograph Saurabh

ARIES, Nainital

November 27, 2014, 9:30 hrs.

Through this project, TIFR-DAA and ARIES will bring together their resource pools for the development of a 0.8 to 2.5 micron Medium Resolution Spectrograph to be used on the main Cassegrain port of 3.6 metre Devasthal Optical Telescope. The instrument called TANSPEC, will provide unique medium resolution (R ~ 2000) spectroscopy capability to the telescope in a broad waveband range of 0.8 to 2.5 microns. It will also have low resolution prism mode (R~200) and a slit viewer with field of view of 1 x 1 arcmin square. This instrument will be extremely sensitive to low temperature stellar photospheres (T ~2500 K) and objects surrounded by warm dust envelopes or embedded in dust/molecular clouds. It is therefore particularly suited to the study of low and very low mass stellar populations (M/L dwarfs, brown dwarfs), strong mass-losing stars on the asymptotic giant branch (AGB), young stellar objects (YSOs) still in their proto-stellar envelopes and active galactic nuclei (AGN). In this talk, I will discuss about the specification and science goal of this instrument along with some recent updates.

Planned Near-IR Instruments for the Thirty Metre Telescope A. N. Ramaprakash

IUCAA, Pune

November 27, 2014, 9:50 hrs.

Two near-IR instruments, IRIS and IRMS are planned for the Thirty Metre Telescope (TMT) at first light. These are both spectrographs with wide ranging capabilities. NFIRAOS, which is the early adaptive optics system on TMT will feed atmosphere-compensated light to the two instruments. This talk will present the planned capabilities of IRIS and IRMS, its science drivers, status as well as Indian participation in their construction.

A Brief Overview of TMT Science Cases G. C. Anupama

IIA, Bengaluru

November 27, 2014, 10:15 hrs.

The talk will provide a brief overview of the science cases proposed to be addressed using the Thirty Meter Telescope. The adaptive optics system of the TMT that will be available from first light will enable imaging and spectroscopy in the infrared at near-diffraction limit of the telescope. Two of the first light instruments will be operational in the NIR region. The talk will present science cases with an emphasis on the NIR region.

Wavelength Calibration for Optical and NIR Astronomy R. K. Banyal IIA, Bengaluru

November 27, 2014, 10:40 hrs.

The focus in extrasolar planet research is now shifting from optical to NIR region due to a better Doppler sensitivity in detecting Earth-size planets around the low mass stars. New spectrographs (e.g. CARMENES and HZPF) are being built to extend planet search programmes into NIR domain and also conduct follow up observations from space missions using radial velocity method. New calibration techniques are necessary to optimize the instrument response in the optical/NIR band. Wavelength calibration should provide Doppler sensitivity reaching 1 m/s level or below. In this talk I will present our laboratory work at Institute for Astrophysics, Gottingen (IAG), of characterizing various emission lamps with high resolution FTS and also generating calibration spectra with Fabry-Perot etalon. We have built a low finesse, Fabry-Perot interferometer (FPI) that provides uniformly distributed spectral lines for optical and NIR band. The FP calibrator maximizes the Doppler information over the full wavelength range of the spectrograph. Though a passive FPI is robust enough to reach the Doppler precision at the level of 1 m/s, long term spectral drifts are still difficult to control. To reach high precision and long-term stability of the FP calibrator, we developed a laser-lock concept to track the dimensional stability of the FPI cavity using frequency stabilized semiconductor diode lasers. The mechanism exploits the high accuracy of optical frequency measurements and connects it to wavelength standards useful in astronomy. In the experiment, the cavity drift down to 10 cm/s can be measured from optical-beat signal obtained from the FP-locked laser and another reference laser locked to the Doppler-free absorption line of the Rb atoms. Such a system has all advantages of the optical frequency comb but built entirely from simpler and off-the-shelf technology.

Session 9 : Future Instrumentation

Infrared Spectroscopic Imaging Survey (IRSIS) experiment S. K. Ghosh

NCRA-TIFR, Pune

November 27, 2014, 11:15 hrs.

The Infrared Spectroscopic Imaging Survey (IRSIS) experiment aims to cover a significant fraction of the sky, with wavelength coverage from 1.7 to 6.4 micron. The primary science goals include: spectral features from components of the ISM which are detectable at a spectral resolution of 100, spectra of stars & census of low mass objects in the solar neighbourhood. The concept of the IRSIS payload (proposed to be launched by ISRO as a "small satellite") is primarily driven by various physical constraints (mass, size, power) of the spacecraft bus. IRSIS comprises of a telescope and a two channel fibre fed spectrometer with an instantaneous field of view in excess of 100 square arc-min. Technological challenges for realizing the IRSIS payload and its current developmental status will be presented.

3.6m aperture Devasthal Optical Telescope M. Gopinathan ARIES, Nainital

November 27, 2014, 11:40 hrs.

ARIES is installing a 3.6m aperture optical telescope in Devasthal close to Nainital. I will be giving an overview and present status of the telescope installation in my oral presentation.

The PRL 2.5m Telescope Abhijit Chakraborty

PRL, Ahmedabad

November 27, 2014, 12:05 hrs.

A new telescope facility of 2.5m aperture will soon be coming up at our Gurushikar Observatory, Mt. Abu. The Astronomy and Astrophysics Division of PRL will be the primary user of the 2.5m Telescope. We expect to see the first light sometime in 2019. The telescope will be primarily used for high cadence observations of 1) near-IR spectroscopic & photometric observations for modeling of transient phenomena like Novae and Super-Novae, and 2) detection of exoplanets using PARAS at sub-1m/s precision. PARAS with the present 1.2m telescope has already demonstrated 1 to 2 m/s precision over a period of two years on bright stars. This will allow PARAS to be one of the ground-based partners of the TESS (Transiting Exoplanet Survey Satellite project by NASA) and the PLATO mission (An ESA project) for planets mass determination. TESS is expected to go up in around 2018 and PLATO around 2022. I will present the parameters of the telescope and the high cadence observation science being planned with the telescope in my talk.