Photometry of stars around SGR A* Virtual Observatory Resource

Authors
  1. Gallego-Cano E.
  2. Fritz T.
  3. Schoedel R.
  4. Feldmeier-Krause A.
  5. Do T.,Nishiyama S.
  6. Published by
    CDS
Abstract

The presence of young massive stars in the Galactic Centre (GC) raises questions about how such stars could form near the massive black hole Sagittarius A* (Sgr A*). Furthermore, the shape of the initial mass function (IMF) in this region seems to differ from its standard Salpeter/Kroupa law. Due to observational challenges such as extreme extinction and crowding, our understanding of the stellar population in this region remains limited, with spectroscopic data available only for selected small and comparably bright sources. We aim to improve our knowledge about the distribution and the IMF of young, massive, stars in the vicinity of Sgr A*. We used intermediate band (IB) photometry to identify candidates for massive young stars. To ensure robust classification, we applied three different, but complementary methods: Bayesian inference, a basic neural network, and a fast gradient-boosted trees algorithm. We obtain spectral energy distributions for 6590 stars, 1181 of which have been previously classified spectroscopically. We identify 351 stars that are classified as early types by all three classification methods, with 155 of them being newly identified candidates. The radial density profiles for late and early-type stars fit well with broken power laws, revealing a break radius of 9.2+/-0.6" for early-type stars. The late-type stars show a core- like distribution around Sgr A* while the density of the early-type stars increases steeply towards the black hole, consistent with previous work. We infer a top-heavy IMF of the young stars near Sgr A* (R<9"), with a power- law of 1.6+/-0.1. At greater distances from Sgr A* a standard Salpeter/Kroupa IMF can explain the data. Additionally, we demonstrate that IB photometry can also constrain the metallicities of late-type stars, estimating metallicities for over 600 late-type stars. The variation of the IMF with radial distance from Sgr A* suggests that different mechanisms of star formation may have been at work in this region. The top-heavy IMF in the innermost region is consistent with star formation in a disc around Sgr A*.

Keywords
  1. galactic-center
  2. infrared-photometry
  3. early-type-stars
  4. infrared-sources
Bibliographic source Bibcode
2024A&A...689A.190G
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/689/A190
IVOA Identifier IVOID
ivo://CDS.VizieR/J/A+A/689/A190
Document Object Identifer DOI
doi:10.26093/cds/vizier.36890190

Access

Web browser access HTML
https://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/689/A190
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/689/A190
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/689/A190
IVOA Table Access TAP
https://tapvizier.cds.unistra.fr/TAPVizieR/tap
Run SQL-like queries with TAP-enabled clients (e.g., TOPCAT).
IVOA Cone Search SCS
For use with a cone search client (e.g., TOPCAT).
https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/689/A190/table?
https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/689/A190/table?
http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/689/A190/table?

History

2024-09-13T11:11:21Z
Resource record created
2024-09-13T11:11:21Z
Created
2024-11-29T20:05:34Z
Updated

Contact

Name
CDS support team
Postal Address
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
E-Mail
cds-question@unistra.fr