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Ammonia surveys of the Galac4c cold interstellar medium
L. Viktor Tóth Eötvös University & Konkoly Observatory
Budapest
In collabora*on with Orsolya Fehér, Alex Kraus and J.-‐P. Bernard, R. Bögner, Y. Doi, E. Falgarone, M. Juvela, J. Malinen, D. J.
Marshall, G. Marton, P. McGehee, L. A. Mon>er, J. Mon>llaud, F. Mo?e, L. Pagani, R. Paladini, V.-‐M. Pelkonen, I. Ristorcelli, A. Rivera-‐Ingraham, S. Pintér, I. Rácz, N. Ysard, E. Verebélyi, S. Zahorecz, A.
Zavagno (Hungarian collaborators with boldface)
Cold ISM traced by molecular lines
The first OH 18cm measurements of dark clouds • High ex>nc>on regions tested (see above) • Carl Heiles 1968ApJ...151..919H
“normal” OH lines detected at several posi>ons • Clouds 1, 2 – today: HCL 1; HCL 2
Heiles Cloud 2 with TMC-‐1
Cloud 1 a.k.a. LDN1251
First molecular line measurements with the 100m telescope already in 1973
• H2CO absorp*on in Heiles 1 and 2 – with Onsala 25-‐m • derive spin temperature from hyperfine structural component
• Programs started at the 100-‐m telescope to observe the H2CO absorp*on line – eg. survey of the Andromeda galaxy
• complex molecules first observed at Effelsberg: methylamine and formamid
• Hachenberg, O., 1974, Naturwissenschaden 61, 537 • Hachenberg, O., 1976, MitAG 39, 44
First ammonia results already in 1977
• Orion BN-‐KL complex • NH3 (1,1); (2,2); (3,3) metastable lines • Mul>ple lines, op>cal depth: 2-‐4 (from hyperfine components) • Non-‐metastable (5,4) line of 14NH3 is detected • Extent of ammonia emigng region is smaller than that of the H2CO • Wilson, Downes, Bieging (1977, BAAS)
Warmed up (50 K < Tkin < 120 K) molecular gas near the Galac4c Centre
discovered with NH3 (1,1); (2,2); (3,3); (4,4) inversion line observa>ons by Güsten, R.; Walmsley, C. M.; Pauls, T. 1981A&A...103..197G
“The Ho and Townes paper”
• The first review of the proper>es and evolu>on of the dense (103cm3 < n(H2) < 105cm3 interstellar medium through NH3 studies
• Ho, P. T. P.; Townes, C. H., 1983ARA&A..21..239H
NH3 rota4onal inversion lines as a thermometer of the CISM
Walmsley, C. M.; Ungerechts, H., 1983A&A...122..164W also refined by Danby, G.; Flower, D. R.; Valiron, P., 1988MNRAS.235..229D
Hot cores
• Non-‐metastable rota>onal NH3 inversion lines
• in Orion-‐KL • Morris, M.; Palmer, P.; Zuckerman, B. 1980ApJ...237....1M
• clarified by Genzel, R.; Ho, P. T. P.; Bieging, J.; Downes, D. 1982ApJ...259L.103G
• detec>ons up to (J, K) = (18,18) toward the galac>c center star forming region Sgr B2; Tkin > Trot > 1300 K Wilson, T. L.; Henkel, C.; Hü?emeister, S. 2006A&A...460..533W
NH3 survey of YSO candidates
• Colour selected IRAS point sources in Ori and Cep
• detected ammonia at 37 of the observed 160 IRAS sources
• detec>on rate higher towards H2O masers
• Embedded YSOs • Wouterloot, J. G. A.; Walmsley, C. M.; Henkel, C. 1988A&A...203..367W
NH3 follow-‐ups of FIR surveys
IRDCs • shadows on the MSX mid-‐IR images • the survey of 218 northern hemisphere high-‐contrast IRDCs • masses up to 1000MSun – sources close to virial equilibrium. • Chira, R.-‐A.; Beuther, H.; Linz, H. et al. 2013A&A...552A..40C ISOPHOT surveys beyond 100μm • Low mass cores in Heiles cloud 2 (Tóth, L. V.; et al., 2004A&A...420..533T) • High mass cores (eg. Bihr, S.; Beuther, H.; Linz, H. 2015A&A...579A..51B)
NH3 follow-‐ups of ATLASGAL
• near mid-‐plane ISM • massive (>100MSun) • dense (N(H2)>105cm-‐3) • cold (Tkin~20K) clumps • Galac>c Molecular Ring • Wienen, M.; Wyrowski, F.; Schuller, F. et al. 2012A&A...544A.146W
Extragalac4c NH3
• NH3 mul>line spectroscopy • lensing galaxy B0218+357 • z = 0.6847 • Tkin ∼ 55 K molecular gas • at about 2kpc from the centre • Henkel, C.; Jethava, N.; Kraus, A. et al. 2005A&A...440..893H
Planck cold clumps (PGCC) – wide range of physical proper4es
• Size: 0.2 pc to 20 pc, and is highly heterogeneous.
• Distribu>on of the angular size: • limited by the Planck resolu>on ∼ 5’ • The maximum size of the compact sources ∼ 12’
• à the associated physical size is totally driven by the distance es>mate.
• The nature of PGCCs: from very compact sources (cloud cores) to large clouds of several pc.
• The range of masses: from 0.3M⊙ up to 2.5 × 104 M⊙
• median mass 88 M⊙. • It covers a broad variety of objects, from cores to giant molecular clouds
• NH3 follow-up survey at Effelsberg-100m Juvela + 2012 A&A...541A..12J The Planck collaboration 2011 A&A...536A..23P The Planck collaboration 2016A&A...594A..28P
Planck Galac*c cold clumps (PGCC) • small extended objects • low dust color temperatures • Planck Collabora>on,
2011A&A...536A..23P • Juvela+ 2012A&A...541A..12J Hydrogen column density distribu*on • from Herschel SPIRE • Density peaks in PGCCs Herschel point sources: Square: 250 μm; Ring: 350 μm X: 500 μm Fehér, Tóth, Ward-‐Thompson et al.
Survey of 50 Planck cold clumps – an example: HCL 2
2016A&A...590A..75F
TMC-‐1 in HCL 2 – pulling the bull’s tail
NH3 mapping (Effelsberg-‐100m) – 2 PGCCs: TMC-‐1 • High S/N, high velocity resolu>on (< 0.05km/s) • La>tude dependent gain measured • (1,1) main group line intensity (5σ), see grayscale • (1,1) line velocity from hyperfine fit (4σ), see colored
• Northern part • Bright in NH3 (1,1) • 3 velocity components
Feher + 2016A&A...590A..75F
TMC-‐1 model: • 4 clumps • 3 sub-‐filaments • Clump 4 with associated YSO
TMC-‐1 in 3D – based on NH3 follow-‐up of PGCCs
• Known YSO with compact ou}low
• Direc>on: >lted to obs. • Length: 0.1pc • High S/N NH3(1,1) & (2,2) à
• Local Tkin increase at YSO: 0.4K • High spectral resolu>on à
• Increased turbulence in sub-‐filament #1 (green)
è 3D model h?ps://www.youtube.com/watch?v=sauawwQi0QM&t=5s
Fehér, Tóth, Ward-‐Thompson et al. 2016A&A...590A..75F
