Massive Stars in the Arches Cluster

By D. Figer, F. Najarro, D. Gilmore, Mark R. Morris, Sungsoo S. Kim, E. Serabyn, I. McLean, A. Gilbert, J. Graham, J. Larkin and 2 more. 2002

250 citations recorded by the source corpus.

We present and use new spectra and narrowband images, along with previously published broadband images, of stars in the Arches cluster to extract photometry, astrometry, equivalent width, and velocity information. The data are interpreted with a wind/atmosphere code to determine stellar temperatures, luminosities, mass-loss rates, and abundances. We have doubled the number of known emission-line stars, and we have also made the first spectroscopic identification of the main sequence for any population in the Galactic center. We conclude that the most massive stars are bona fide Wolf-Rayet (W-R) stars; are some of the most massive stars known, having Minit > 100 M☉; and have prodigious winds, Ṁ > 10-5 M☉ yr-1, that are enriched with helium and nitrogen; with these identifications, the Arches cluster contains about 5% of all known W-R stars in the Galaxy. We find an upper limit to the velocity dispersion of 22 km s-1, implying an upper limit to the cluster mass of 7 × 104 M☉ within a radius of 0.23 pc; we also estimate the bulk heliocentric velocity of the cluster to be vcluster, ☉ ≈ +95 km s-1. Taken together, these results suggest that the Arches cluster was formed in a short, but massive, burst of star formation about 2.5 ± 0.5 Myr ago, from a molecular cloud that is no longer present. The cluster happens to be approaching and ionizing the surface of a background molecular cloud, thus producing the thermal arched filaments. We estimate that the cluster produces 4 × 1051 ionizing photons s-1, more than enough to account for the observed thermal radio flux from the nearby cloud, 3 × 1049 ionizing photons s-1. Commensurately, it produces 107.8 L☉ in total luminosity, providing the heating source for the nearby molecular cloud, Lcloud ≈ 107 L☉. These interactions between a cluster of hot stars and a wayward molecular cloud are similar to those seen in the "Quintuplet/Sickle" region. The small spread of formation times for the known young clusters in the Galactic center and the relative lack of intermediate-age stars (τage = 107.0-107.3 yr) suggest that the Galactic center has recently been host to a burst of star formation. Finally, we have made new identifications of near-infrared sources that are counterparts to recently identified X-ray and radio sources.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/89c59634dae46be8e252765d41031bfabf674523

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In Astronomy and Astrophysics

1. T. Alexander
2. N. Smith
3. P. Crowther
4. G. Meynet
5. R. Genzel
6. F. Najarro
7. J. Vink
8. Andre Maeder

In Instrumentation

1. N. Smith
2. P. Crowther
3. R. Hirschi
4. T. Alexander
5. J. Vink
6. G. Meynet
7. F. Najarro
8. A. Herrero

Citations in the corpus

• Massive Perturber-driven Interactions between Stars and a Massive Black Hole (2006, background): “About10 young stellar clusters with masses in the range102–105M⊙ and sizes of orderRp ∼ 1 pc were observationally identified (Figer et al. 1999, 2002; Maillard et al. 2004; Figer et al. 2004; Borissova et al. 2005).”
• A census of the Carina Nebula — I. Cumulative energy input from massive stars (2006, background): “…the results would be identicalto NG C3603 within the uncertainties.Carina has about 25{30% ofthe totalionizing ux ofthem ore m assive Archesclusterin theG alactic center (Figer et al.2002),and roughly 25% ofboth the total Q H and LS W ofR136 in 30 D oradusgiven by Crowther & D essart (1998).”
• On the massive stellar population of the super star cluster Westerlund 1 (2005, background): “The high luminosity and hence mass inferred for the YHGs suggest an age of ∼4 Myrs (Clark & Negueruela 2002, and refs. therein), while following Figer et al. (2002) the presence of relatively cool emission line B supergiants implies an age ≥4 Myr.”
• The relation between the most-massive star and its parental star cluster mass (2009, unknown): “…et al. (2007); Ortolani et al. (2008), 60: Bonatto et al. (2006); Wolff et al. (2007), 61: Knödlseder (2000); Massey et al. (2001); Wolff et al. (2007); Negueruela et al. (2008), 62: Figer et al. (2002); Martins et al. (2008), 63: Massey & Hunter (1998); Selman et al. (1999); Schnurr et al. (2009)”
• The most massive stars in the Arches cluster (2007, methodology): “From K-band spectroscopy of the brightest members, Blum et al. (2001) and Figer et al. (2002) identified several late WN stars and early O supergiants.”
• A Massive Cluster of Red Supergiants at the Base of the Scutum-Crux Arm (2007, background): “…Context of Astrophysics From the cluster mass and age derived here, RSGC2 joins the nearby RSGC1 (FMR06), Wd 1 (Clark et al. 2005), the Arches (Figer et al. 2002), Quintuplet (Figer et al. 1999), and Galactic center (Figer et al. 2004) clusters, in a growing list of Galactic analogs to…”
• The dynamical evolution of molecular clouds near the Galactic Centre - I. Orbital structure and evolutionary timeline (2014, background): “The Arches has a line-of-sight velocity ofvlos = 109 ± 8 km s−1 in the Galactic reference frame (Figer et al. 2002) and a proper motion ofvpm = 172 ± 15 km s−1 with respect to the background field stellar population, almost entirely in theGalactic plane towards increasing longitudes (Clarkson et…”
• Globular clusters as the relics of regular star formation in ‘normal’ high-redshift galaxies (2015, background): “…clusterswas thought to be exclusive to galaxy mergers or merger remnants (e.g.Ashman & Zepf 1992), but YMCs have now been seen in a variety of high-pressure environments, including starburst dwarfg laxies and galaxy centres (e.g.Figer, McLean & Morris 1999; Figer et al. 2002; Anders et al. 2004).”
• The R136 star cluster hosts several stars whose individual masses greatly exceed the accepted 150 M⊙ stellar mass limit (2010, methodology): “Martins et al. (2008) based their analysis upon HST/NICMOS photometry from Figer et al. (2002) together with a (low) Galactic Centre distance of 7.6 kpc from Eisenhauer et al. (2005) plus a (low) foreground extinction of AKs = 2.8 mag from Stolte et al. (2002).”
• An Extended Star Formation History for the Galactic Center from Hubble Space Telescope NICMOS Observations (2003, methodology): “All three clusters are quite similar in most respects, except for age; the Central and Quintuplet clusters are ≈ 3−5 Myr old (Figer et al. 1999a; Krabbe et al. 1995; Najarro et al. 1997), while the Arches cluster is substantially younger, τage = 2.5±0.5 Myr (Figer et al. 2002).”
• Stellar Orbits around the Galactic Center Black Hole (2003, background): “This hypothesis has been investigated numerically by Kim & Morris (2003) and Portegies-Zwart et al. (2003), who clarify that very massive clusters are required: 105–106 M , far more massive than even the extreme (for our Galaxy) Arches and Quintuplet clusters (e.g., Figer et al. 1999, 2002).”
• Mass Loss: Its Effect on the Evolution and Fate of High-Mass Stars (2014, methodology): “For the Milky Way, LMC, and SMC, various studies using modern non-LTE analysis find fcl ≃ 10 (Crowther et al. 2002, Evans et al. 2004, Figer et al. 2002, Hillier et al. 2003, Massa et al. 2003, Puls et al. 2006), corresponding to Ṁ reductions by a factor of ∼3 with typical uncertainties of ∼30%.”
• Stellar evolution with rotation XI. Wolf-Rayet star populations at different metallicities (2004, background): “This region of the Milky Way is very rich in massive stars (according to Figer et al. 2002, the Arches cluster contains about 5% of all known WR stars in the Galaxy) and it is thus interesting to derive the properties of the WR stars predicted by the present rotating models.”
• Stellar and wind properties of massive stars in the central parsec of the Galaxy (2006, background): “Even more interesting is the difference in their ages: 2.5, 4 and 6 Myr for the Arches, the Quintuplet and the central cluster respectively (Figer et al. 1999, 2002; Paumard et al. 2006).”
• A 20 Centimeter Survey of the Galactic Center Region. I. Detection of Numerous Linear Filaments (2004, background): “These HII regions are thought to be ionized by two massive clusters of hot stars known as the Arches and the Quintuplet clusters (e.g. Cotera et al. 1996; Serabyn, Shupe and Figer 1998; Figer et al. 2002).”
• Young Massive Star Clusters (2010, background): “Two well known examples of resolved YMCs are the Arches and Quintuplet clusters near the Galactic center (Figer et al. 2002, Figer, McLean & Morris 1999).”
• Mass loss from hot massive stars (2008, methodology): “If CL4 is set to unity, the wind will be unclumped in the outermost region (as suggested by Nugis et al 1998 and adopted by Figer et al 2002 and Najarro et al 2004 for the case of WR-winds, see above).”
• Star formation rates and efficiencies in the Galactic Centre (2017, background): “Figer, McLean & Morris (1999a) and Figer et al. (2002) estimate that the luminosity within the Arches and Quintuplet clusters is 107.8 and 107.5 L , respectively.”