Open clusters in VVV

Formation and Evolution of Star Clusters in Chile, May 14th - 16th, ESO-Chile

Jura Borissova Universidad de Valparaiso Millennium Institute of Astrophysics, MAS

Short list of (most active) collaborators

Sebastian Ramirez (U. Valparaíso) Andre Nicolas Chenè (Gemini North) Pia Amigo (U. Valparaíso) Claudio Navarro (U. Valparaíso) James Alexander Clarke (U. of Hertfordshire) Radostin Kurtev (U. Valparaíso) Daniel Majaess (Saint Mary’s University, Canada) Margaret Hanson (Univ. Cincinnati) Bogdan Popescu (Univ. Cincinnati) V. D. Ivanov, (ESO, Chile) Charles Bonatto (UFRGS, Brazil) Christian Moni Bidin (U. Concepción) VVV star cluster team.

Dante Minniti (PUC de Chile), PI VVV Phil Lucas (U. of Hertfordshire), PI VVV Jim Emerson (Queen Mary, UK) D. Geisler (Univ. Concepcion)

Star cluster meeting , May 2014, ESO.

Outline of Valparaiso’s star cluster group topics

Census. Building a database of large, homogeneous sample

of fundamental parameters (distance, age, etc.) of obscured stellar clusters in VVV area – S. Ramirez, P. Amigo, A. Chene, Saurabh, J. Clarke…

Young massive clusters, young massive stars – Sebastian Ramirez

Old open clusters Variable stars, variable YSO – Claudio Navarro,

Nicolas Medida, Pia Amigo A multiwavelength view on star formation around

Galactic star clusters from VVV catalog – Pia Amigo Proper motion and X-ray mach of selected star

forming regions in VVV – Michael Kuhn.

Star cluster meeting , May 2014, ESO.

Some goals

• Provide a distribution map of these star clusters throughout the Galaxy.

• Constrain the fundamental parameters on the very early stages (up to 10 Myr).

• Study the effect of Galactic position on cluster evolution.

• Trace the structure of the Galactic disk.

• Many more…

Star cluster meeting , May 2014, ESO.

Census: Pointed visual inspection of the VVV

disk area.

Goal: to trace the early epochs of star cluster evolution. 96 new star clusters in the Galactic disk (Borissova el al. 2011).

Star cluster meeting , May 2014, ESO.

Census: Visual inspection of the VVV central area

58 new star clusters in the inner 10 degrees around Galactic center. (Borissova el al. 2014, in press).

Star cluster meeting , May 2014, ESO.

Reddening, distance, age, [Fe/H], mass, etc. Methods: •Photometric Parallax: Isochrone fitting of color-magnitude diagrams. Best solution of Main sequence isochrones + PMS set. Spectroscopic parallax: Low and medium resolution spectra in K, and J+H (when available) bands: ISAAC, SofI, SOAR, MMIRS, KMOS… •Proper motion – memberships – for the moment: PM catalogs, starting with VVV. •Radial velocities – memberships and mean RV of the clusters.

Building a database:

Building a database: Up to 05.2014 – 32 published clusters. Some typical CMDs:

CMDs of Danks1, Danks2, RCW 79 and DBS2003 132 (Chenè et al. 2012).

CMDs of CL152 and CL154 (Borissova et al. 2014).

Some interesting cases for the central area:

CMDs of CL139 and CL140: binary at 3.8 kpc? (Borissova et al. 2014) 8019 Myr and 1.30.3Gyr.

Some interesting cases: CL117, CL130 and CL161 – RSC?

CMDs of CL117, CL130 and CL161: RSC at 11.8, 1.8 and 3.5 kpc? (Borissova et al. 2014).

Some interesting cases: CL119, CL143 and CL150 : new bulge GC?

CMDs of CL119, CL143 and CL150: new GC at 6.8 (51.2Gyr), 7.8 (40.7Gyr) and 6.7(100.8 Gyr) kpc? (Borissova et al. 2014).

Some interesting cases: Detached dust shell around WR60-6 star in VVV CL036.

Sub-mm observations of 12CO(3 → 2) APEX observations: emission in the region •System velocity of -45.7±2.3 km/s. •The infrared SED of the shell is best-fit by a blackbody function with a temperature of 122±12K. •The shell is 28000 years old. •The central star, WR60-6, displays variability in the Ks band that is possibly cyclic with a tentative period of 0.4324 days. •The estimated mass of dust in the nebular shell lead to the conclusion that the material in the shell most probably was ejected in previous stages of evolution of WR60-6.

(Borissova et al. 2014).

Some early comparisons:

The VVV survey area, overplotted on the GLIMPSE 3.6, 4.5 and 8.0 μm true color image, with the new star cluster candidates positions(Borissova el al. 2011, plot R. Barba).

Correlation between GLIMPSE dust structures and projected position of our star cluster candidates. Sample: 154 newly discovered clusters.

Some early comparisons: Characteristic of the sample: 154 newly discovered clusters.

Upper panel: Distribution of the projected angular size of disk and central clusters (Borissova et al 2011, 2014). Lower panel: Histogram of the cluster sample by number of most probable cluster members (Borissova el al. 2014).

The mean radius of the disk sample is 34”±18 the mean radius of the central clusters area 36”±14. Smaller than the mean values of 47” ± 17 , and 42” ± 22 From Dutra et al. (2003) and Mercer et al. (2005) clusters for the VVV area. Most of the clusters have a radius between 20 and 30” faint and compact clusters.

Some early comparisons:

The comparison between the E(J − Ks) in our sample with this derived from RC stars in Gonzalez et al. (2011, 2012). The relation between the age of open clusters and derived metallicity [Fe/H] for our sample.

The relation between the age of open clusters and distance from the Galactic plane Z for our sample (red) and Tadross (2011, blue).

Combination of sp. paralax + Isochrone fitting of MS y PMS (Geneva + Siess 2000) database.

DR2: Poorly populated MS. PMS and IR excess stars.

Robitaille et al. 2006

Variability: DR2 Obj1 :46 epochs, no variability Obj2 : 62 epochs, no period, but variability, Amp(K)= 0.63; K<mean>=12.78 0.10 SOAR, OSIRIS, R~1200

Open clusters with emission line stars and YSO in the VVV area:

VVV CL012

VVV CL013

DR2: PMS and IR excess stars: PMS cluster

Robitaille et al. 2006

Variability: DR2 Obj1 : saturated! Obj2 : 48 epochs, no period, possible variability, Amp (K)= 0.2; K<mean>=12.17 0.12

G300.3412-00.2190 SOAR, OSIRIS, R~1200

[DBS2003] 75

DR2: poorly populated MS, if any, embedded?

Robitaille et al. 2006

Variability: DR2 Obj1 : 52 epochs, Variable, no period.

SofI, NTT

[DBS2003] 93

DR2: some RG, poor MS, PMS.

Robitaille et al. 2006

Variability: DR2 Obj1 : saturated! Obj2: saturated!

SofI, NTT, R~2500

[DBS2003] 130

This cluster is projected in the G305 region. DR2: MS, PMS.

Variability: DR2 Obj1 : saturated! Obj2: DR2, 65 epochs, variable, Am K=0.55, brightness is decreasing in this period

SofI, NTT: The Obj1 is classified as O8-B0Ie, while Obj2 is most probably B0Ve type star.

Future work:

Completing the sample (~100) with HOMEGENIOUSLY derived fundamental parameters.

Time domain:

• variability

• proper motions

Thank you.

JB, SRA,PA,CN are supported by FONDECYT No.1120601 and Ministry of Economy, Development, and Tourism's

Millennium Science Initiative through grant IC12009, awarded to The Millennium Institute of Astrophysics, MAS. S.R.A. is supported by the FONDECYT project No. 3140605. P.A. acknowledges the support by ALMA-CONICYT project number No. 31110002. RK is spported by Fondecyt Reg. No. 1130140 and Cento de Astrofísica de Valparaíso.