Properties of the Remnant Clockwise Disk of Young Stars in the Galactic Center

Yelda, S.; Ghez, A. M.; Lu, Jessica R.; Do, Tuan; Meyer, L.; Morris, Mark; Matthews, K.

doi:10.1088/0004-637x/783/2/131

Cited by 169 publications

(366 citation statements)

References 81 publications

Supporting

Mentioning

307

Contrasting

Order By: Relevance

“…The simplest in situ formation scenarios initially produce circular orbits since gas that flows in at low or moderate rates circularizes prior to the onset of star formation (Nayakshin & Cuadra 2005;Alexander et al 2007;Löckmann et al 2009). The observed eccentricity distribution peaks at e=0.3 Yelda et al 2013). Scenarios invoking more rapid gas inflow, such as the infall of a single molecular cloud or the collision of two molecular clouds, could produce disk stars with large initial eccentricities and have the added bonus of producing a large population of young stars off the disk (Bonnell & Rice 2008;Wardle & Yusef-Zadeh 2008;Hobbs & Nayakshin 2009;Mapelli et al 2012), similar to what has been observed (Paumard et al 2006;Bartko et al 2009;Lu et al 2009;Yelda et al 2013).…”

Section: The Young Nuclear Clustersupporting

confidence: 77%

“…The observed eccentricity distribution peaks at e=0.3 Yelda et al 2013). Scenarios invoking more rapid gas inflow, such as the infall of a single molecular cloud or the collision of two molecular clouds, could produce disk stars with large initial eccentricities and have the added bonus of producing a large population of young stars off the disk (Bonnell & Rice 2008;Wardle & Yusef-Zadeh 2008;Hobbs & Nayakshin 2009;Mapelli et al 2012), similar to what has been observed (Paumard et al 2006;Bartko et al 2009;Lu et al 2009;Yelda et al 2013). However, the evolution of an initially circular disk over 4-6 Myr depends on the initial mass function (IMF) of the stars and it is possible to evolve to today's observed distribution for moderately top-heavy IMFs .…”

Section: The Young Nuclear Clustermentioning

confidence: 87%

“…These surveys are deep enough to identify B main-sequence stars; however, they have very small fields of view (∼2"), which has led to incomplete spatial coverage (Figure 1). Proper motions and radial velocities of the young stars have revealed coherent dynamical structures, including one well-defined inner disk (Genzel et al 2000;Levin & Beloborodov 2003;Paumard et al 2006), and there is continued discussion on the possibility of a disk warp or a second disk (Genzel et al 2003;Bartko et al 2009;Lu et al 2009;Yelda et al 2013).…”

Section: The Young Nuclear Clustermentioning

confidence: 99%

See 2 more Smart Citations

Young stars in the Galactic center

Lu¹,

Ghez

Morris

et al. 2013

Proc. IAU

View full text Add to dashboard Cite

Abstract. The central parsec of our Galaxy hosts not only a supermassive black hole, but also a large population of young stars (age <6 Myr) whose presence is puzzling given how inhospitable the region is for star formation. The strong tidal forces require gas densities many orders of magnitude higher than is found in typical molecular clouds. Kinematic observations of this young nuclear cluster show complex structures, including a well-defined inner disk, but also a substantial off-disk population. Spectroscopic and photometric measurements indicate the initial mass function (IMF) differs significantly from the canonical IMF found in the solar neighborhood. These observations have led to a number of proposed star formation scenarios, such as an infalling massive star cluster, a single infalling molecular cloud, or cloud-cloud collisions. I will review recent works on the young stars in the central parsec and discuss connections with young nuclear star clusters in other galaxies, such as M31, and with star formation in the larger central molecular zone.

show abstract

Section: The Young Nuclear Clustersupporting

confidence: 77%

Section: The Young Nuclear Clustermentioning

confidence: 87%

Section: The Young Nuclear Clustermentioning

confidence: 99%

See 1 more Smart Citation

Young stars in the Galactic center

Lu¹,

Ghez

Morris

et al. 2013

Proc. IAU

View full text Add to dashboard Cite

show abstract

“…The trajectories of young stars are known from proper motion measurements in the near-IR. To see if these stars have radio continuum counterparts, their positions at the epoch of our 34 GHz observation on 2014 March 9 (2014.19) have been calculated based on proper motions and orbital accelerations have been derived from near-IR observations (Lu et al 2009;Gillessen et al 2009;Yelda et al 2014). Tables 2 and 3 give the positions of the S-cluster and their corresponding positional uncertainties at the epoch of 2014.19 and from two different catalogs (Gillessen et al 2006;Lu et al 2009).…”

Section: Radio Emission From the S Clustermentioning

confidence: 99%

SGR A* and Its Environment: Low-Mass Star Formation, the Origin of X-Ray Gas and Collimated Outflow

Yusef‐Zadeh

Wardle

Schödel

et al. 2016

ApJ

View full text Add to dashboard Cite

We present high-resolution multiwavelength radio continuum images of the region within 150″ of SgrA * , revealing a number of new extended features and stellar sources in this region. First, we detect a continuous 2″ east-west ridge of radio emission, linking SgrA * and a cluster of stars associated with IRS 13 N and IRS 13E. The ridge suggests that an outflow of east-west blob-like structures is emerging from SgrA * . In particular, we find arc-like radio structures within the ridge with morphologies suggestive of photoevaporative protoplanetary disks. We use infrared K s and L′ fluxes to show that the emission has similar characteristics to those of a protoplanetary disk irradiated by the intense radiation field at the Galactic center. This suggests that star formation has taken place within the S-cluster 2″ from SgrA * . We suggest that the diffuse X-ray emission associated with Sgr A * is due to an expanding hot wind produced by the mass loss from B-type main sequence stars, and/or the disks of photoevaporation of low mass young stellar objects (YSOs) at a rate of ∼10 −6  M yr −1 . The proposed model naturally reduces the inferred accretion rate and is an alternative to the inflow-outflow style models to explain the underluminous nature of Sgr A * . Second, on a scale of 5″ from Sgr A * , we detect new cometary radio and infrared sources at a position angle PA∼50°which is similar to that of two other cometary sources X3 and X7, all of which face Sgr A * . In addition, we detect a striking tower of radio emission at a PA∼50°-60°along the major axis of the Sgr A East supernova remnant shell on a scale of 150″ from Sgr A * . We suggest that the cometary sources and the tower feature are tracing interaction sites of a mildly relativistic jet from Sgr A * with the atmosphere of stars and the nonthermal Sgr A East shell at a PA∼50°-60°with´-, and opening angle 10°. Lastly, we suggest that the east-west ridge of radio emission traces an outflow that is potentially associated with past flaring activity from Sgr A * . The position angle of the outflow driven by flaring activity is close to −90°.

show abstract

“…The images were centered near the position of Sgr A* and span 10 arcseconds (∼ 0.4 pc at R 0 ≈ 8.0 kpc), and were taken over 37 nights between July 2004 and May 2016 (observation setup used here is further detailed by Ghez et al 2008 andYelda et al 2014). …”

mentioning

confidence: 99%

Constraining the Variability and Binary Fraction of Galactic Center Young Stars

Gautam

Ghez

et al. 2016

Proc. IAU

View full text Add to dashboard Cite

Abstract. We present constraints on the variability and binarity of young stars in the central 10 arcseconds (∼ 0.4 pc) of the Milky Way Galactic Center (GC) using Keck Adaptive Optics data over a 12 year baseline. Given our experiment's photometric uncertainties, at least 36% of our sample's known early-type stars are variable. We identified eclipsing binary systems by searching for periodic variability. In our sample of spectroscopically confirmed and likely early-type stars, we detected the two previously discovered GC eclipsing binary systems. We derived the likely binary fraction of main sequence, early-type stars at the GC via Monte Carlo simulations of eclipsing binary systems, and find that it is at least 32% with 90% confidence.Keywords. Galaxy: center, stars: early-type, (stars:) binaries: eclipsingIn this work, we better constrain the Milky Way Galactic Center (GC) binary fraction with much larger samples, improving upon previous studies limited to the brightest sources. Tighter binary fraction constraints are especially useful to understand the formation and dynamics of young stars in the nuclear star cluster near the central supermassive black hole: The fragmentation of an accretion disk around the black hole could have formed the young stars currently observed in the clockwise disk at the GC (Alexander et al. 2008). The binary fraction also constrains the binary disruption mechanism (Hills 1988) that could explain the origin of the observed young S-stars within ∼ 0.05 pc of the central supermassive black hole.We used laser guide-star adaptive optics high-resolution images of the GC obtained at the 10 m. W. M. Keck II telescope with the NIRC2 near-infrared facility imager through the K (λ 0 = 2.124 µm) bandpass. The images were centered near the position of Sgr A* and span 10 arcseconds (∼ 0.4 pc at R 0 ≈ 8.0 kpc), and were taken over 37 nights between July 2004 and May 2016 (observation setup used here is further detailed by Ghez et al. 2008 andYelda et al. 2014).Variable stars were identified as those displaying photometric fluctuations above that expected from 7σ noise fluctuations. At least 36% of the 72 known early-type stars identified in all nights are variable.To identify eclipsing binaries, we conducted a periodic variability search on 124 spectroscopically confirmed or likely early-type stars (p(Early-Type) 0.5, from Do et al.1

show abstract

Properties of the Remnant Clockwise Disk of Young Stars in the Galactic Center

Cited by 169 publications

References 81 publications

Young stars in the Galactic center

Young stars in the Galactic center

SGR A* and Its Environment: Low-Mass Star Formation, the Origin of X-Ray Gas and Collimated Outflow

Constraining the Variability and Binary Fraction of Galactic Center Young Stars

Contact Info

Product

Resources

About