Star Formation in the Central 400 pc of the Milky Way: Evidence for a Population of Massive YSOs

Abstract

The central kpc of the Milky Way might be expected to differ significantly from the rest of the Galaxy with regard to gas dynamics and the formation of YSOs. We probe this possibility with mid-infrared observations obtained with IRAC and MIPS on Spitzer and with MSX. We use color-color diagrams and SED fits to explore the nature of YSO candidates (including objects with 4.5 micron excesses possibly due to molecular emission). There is an asymmetry in the distribution of the candidate YSOs, which tend to be found at negative Galactic longitudes; this behavior contrasts with that of the molecular gas, approximately 2/3 of which is at positive longitudes. The small scale height of these objects suggests that they are within the Galactic center region and are dynamically young. They lie between two layers of infrared dark clouds and may have originated from these clouds. We identify new sites for this recent star formation. The methanol masers appear to be associated with young, embedded YSOs characterized by 4.5 micron excesses. We use the SEDs of these sources to estimate their physical characteristics. Within the central 400x50 pc (|l|<1.3\degr and |b|<10') the star formation rate based on the identification of Stage I evolutionary phase of YSO candidates is about 0.14 solar mass/yr. We suggest that a recent burst of star formation took place within the last 10^5 years. This suggestion is also consistent with estimates of star formation rates within the last ~10^7 years showing a peak around 10^5 years ago. Lastly, we find that the Schmidt-Kennicutt Law applies well in the central 400 pc of the Galaxy. This implies that star formation does not appear to be dramatically affected by the extreme physical conditions in the Galactic center region.

arXiv comment96 pages, ten tables, 35 figures, ApJ (in press), replaced by a revised version

References in corpus (50)

• On the variation of the Initial Mass Function
• Star Formation in Galaxies Along the Hubble Sequence
• Measuring Distance and Properties of the Milky Way's Central Supermassive Black Hole with Stellar Orbits
• Infrared Emission from Interstellar Dust. II. The Diffuse Interstellar Medium
• Interpreting Spectral Energy Distributions from Young Stellar Objects. II. Fitting observed SEDs using a large grid of pre-computed models
• Interpreting Spectral Energy Distributions from Young Stellar Objects. I. A grid of 200,000 YSO model SEDs
• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• Determining Star Formation Rates for Infrared Galaxies
• 2-D Radiative Transfer in Protostellar Envelopes: I. Effects of Geometry on Class I Sources
• A Catalog of Extended Green Objects (EGOs) in the GLIMPSE Survey: A new sample of massive young stellar object outflow candidates
• 2-D Radiative Transfer in Protostellar Envelopes: II. An Evolutionary Sequence
• The SCUBA Legacy Catalogue: Continuum Objects Detected by SCUBA
• HST/NICMOS Observations of Massive Stellar Clusters Near the Galactic Center
• Infrared Extinction Toward Nearby Star-Forming Regions
• A Spitzer Space Telescope Infrared Survey of Supernova Remnants in the Inner Galaxy
• Absolute Calibration and Characterization of the Multiband Imaging Photometer for Spitzer. II. 70 micron Imaging
• Hot and Diffuse Clouds near the Galactic Center Probed by Metastable H3+
• A deep submillimetre survey of the Galactic Centre
• The Mid-Infrared Extinction Law in the Ophiuchus, Perseus, and Serpens Molecular Clouds
• IR Dust Bubbles: Probing the Detailed Structure and Young Massive Stellar Populations of Galactic HII Regions
• A $\lambda$20cm Survey of the Galactic Center Region I: Detection of Numerous Linear Filaments
• The Origin of Diffuse X-ray and $\gamma$-ray Emission from the Galactic Center Region: Cosmic Ray Particles
• Massive Protostars in the Infrared Dark Cloud MSXDC G034.43+00.24
• A Radio Polarimetric Study of the Galactic Center Threads
• The AST/RO Survey of the Galactic Center Region. I. The Inner 3 Degrees
• An Initial Look at the Far Infrared-Radio Correlation within Nearby Star-forming Galaxies using the Spitzer Space Telescope
• High-Resolution, Wide-Field Imaging of the Galactic Center Region at 330 MHz
• On the Formation of Compact Stellar Disks Around Sgr A*
• Outflows from Massive YSOs as Seen with the Infrared Array Camera
• Detection of new sources of methanol emission at 95 GHz with the Mopra telescope
• Point Sources from a Spitzer IRAC Survey of the Galactic Center
• ISOGAL: A deep survey of the obscured inner Milky Way with ISO at 7 and 15 micron and with DENIS in the near-infrared
• Caught in the act: The Onset of massive star formation
• The Nature of the Molecular Environment within 5 pc of the Galactic Center
• Spectral imaging of the Sagittarius B2 region in multiple 3-mm molecular lines with the Mopra telescope
• Three New Supernova Remnant OH Masers Near the Galactic Center: Evidence for Large Scale Maser Emission from Supernova Remnants
• GBT Multiwavelength Survey of the Galactic Center Region
• X-ray Observations of Stellar Clusters Near the Galactic Center
• A Schmidt-Kennicutt law for star formation in the Milky Way disk
• Morphologies of Ultracompact HII Regions in W49A and Sgr B2: Prevalence of Shells and a Modified Classification Scheme
• Is the Cepheus E Outflow driven by a Class 0 Protostar?
• Planetary Nebulae Near the Galactic Center: Identifications
• NTT infrared imaging of star cluster candidates towards the central parts of the Galaxy
• Simulations of Mixed Morphology Supernova Remnants With Anisotropic Thermal Conduction
• A Catalog of 24um Sources Toward the Galactic Center
• The Nature of Nonthermal X-ray Filaments Near the Galactic Center
• The Mid-Infrared Colors of the ISM and Extended Sources at the Galactic Center
• Radio Observations of New Galactic Bulge Planetary Nebulae
• Recent star formation in the inner Galactic Bulge seen by ISOGAL. I - Classification of bright mid-IR sources in a test field
• Masers as Probes of Massive Star Formation in the Nuclear Disk

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• Possible connection between the asymmetry of North Polar Spur and Loop I with Fermi Bubbles
• A multiwavelength study of star formation in the vicinity of Galactic HII region Sh2-100
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• CMZoom II: Catalog of Compact Submillimeter Dust Continuum Sources in the Milky Way's Central Molecular Zone
• Chemical evolution of the Galactic Center
• The Life Cycle of the Central Molecular Zone. II: Distribution of atomic and molecular gas tracers
• Constraining the population of isolated massive stars within the Central Molecular Zone
• Submillimeter imaging of the Galactic Center starburst Sgr B2. Warm molecular, atomic, and ionized gas far from massive star-forming cores
• Prospects of 3D mapping of the Galactic Centre clouds with X-ray polarimetry
• Signatures of Young Star Formation Activity Within Two Parsecs of Sgr A*
• SOFIA/FORCAST Galactic Center Legacy Survey: Overview
• SOFIA/HAWC+ Far-Infrared Polarimetric Large-Area CMZ Exploration (FIREPLACE) Survey III: Full Survey Data Set
• Structural Analogs of the Milky Way Galaxy: Stellar Populations in the Boxy Bulges of NGC 4565 and NGC 5746
• Hydrodynamic simulations of the central molecular zone with realistic Galactic potential
• A global view on star formation: The GLOSTAR Galactic plane survey IV. Radio continuum detections of young stellar objects in the Galactic Centre region
• The CARMA 3mm Survey of the Inner $0.7^{\circ }\times 0.4^{\circ }$ of the Central Molecular Zone
• Near-infrared spectroscopic observations of massive young stellar object candidates in the Central Molecular Zone
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