G0.253 + 0.016: A MOLECULAR CLOUD PROGENITOR OF AN ARCHES-LIKE CLUSTER

Journal Article · Mon Feb 20 00:00:00 EST 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/746/2/117· OSTI ID:22011742

Longmore, Steven N; Ascenso, Joana; Testi, Leonardo; Bressert, Eli ^[1]; Rathborne, Jill ^[2]; Bastian, Nate ^[3]; Alves, Joao; Meingast, Stefan ^[4]; Bally, John; Battersby, Cara ^[5]; Longmore, Andy ^[6]; Purcell, Cormac ^[7]; Walsh, Andrew ^[8]; Jackson, James; Foster, Jonathan ^[9]; Molinari, Sergio ^[10]; Amorim, A; Lima, J; Marques, R; Moitinho, A ^[11] ; others, and

---

1. European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching bei Munchen (Germany)
2. CSIRO Astronomy and Space Science, Epping, Sydney (Australia)
3. Excellence Cluster Universe, Boltzmannstr. 2, 85748 Garching (Germany)
4. Institute of Astronomy, University of Vienna, Tuerkenschanzstrasse 17, 1180 Vienna (Austria)
5. Center for Astrophysics and Space Astronomy, University of Colorado, UCB 389, Boulder, CO 80309 (United States)
6. UK Astronomy Technology Centre, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom)
7. School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom)
8. Department of Astronomy, James Cook University, Townesville (Australia)
9. Institute for Astrophysical Research, Boston University, Boston, MA 02215 (United States)
10. INAF-Istituto Fisica Spazio Interplanetario, Via Fosso del Cavaliere 100, I-00133, Rome (Italy)
11. SIM, Faculdade de Ciencias da Universidade de Lisboa, Ed. C8. Campo Grande 1749-016 Lisbon (Portugal)

Young massive clusters (YMCs) with stellar masses of 10{sup 4}-10{sup 5} M{sub Sun} and core stellar densities of 10{sup 4}-10{sup 5} stars per cubic pc are thought to be the 'missing link' between open clusters and extreme extragalactic super star clusters and globular clusters. As such, studying the initial conditions of YMCs offers an opportunity to test cluster formation models across the full cluster mass range. G0.253 + 0.016 is an excellent candidate YMC progenitor. We make use of existing multi-wavelength data including recently available far-IR continuum (Herschel/Herschel Infrared Galactic Plane Survey) and mm spectral line (H{sub 2}O Southern Galactic Plane Survey and Millimetre Astronomy Legacy Team 90 GHz Survey) data and present new, deep, multiple-filter, near-IR (Very Large Telescope/NACO) observations to study G0.253 + 0.016. These data show that G0.253 + 0.016 is a high-mass (1.3 Multiplication-Sign 10{sup 5} M{sub Sun }), low-temperature (T{sub dust} {approx} 20 K), high-volume, and column density (n {approx} 8 Multiplication-Sign 10{sup 4} cm{sup -3}; N{sub H{sub 2}}{approx}4 Multiplication-Sign 10{sup 23} cm{sup -2}) molecular clump which is close to virial equilibrium (M{sub dust} {approx} M{sub virial}) so is likely to be gravitationally bound. It is almost devoid of star formation and, thus, has exactly the properties expected for the initial conditions of a clump that may form an Arches-like massive cluster. We compare the properties of G0.253 + 0.016 to typical Galactic cluster-forming molecular clumps and find it is extreme, and possibly unique in the Galaxy. This uniqueness makes detailed studies of G0.253 + 0.016 extremely important for testing massive cluster formation models.

• OSTI ID: 22011742
• Journal Information: Astrophysical Journal, Vol. 746, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTRONOMY
GALACTIC EVOLUTION
GALAXIES
MASS
PROTOSTARS
STAR CLUSTERS
STAR EVOLUTION
STARS
TELESCOPES
WATER