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J/A+A/609/A26       Galactic Center old stars distribution (Gallego-Cano+, 2018)

The distribution of old stars around the Milky Way's central black hole. I. Star counts. Gallego-Cano E., Schoedel R., Nogueras-Lara F., Gallego-Calvente A.T., Amaro-Seoane P., Baumgardt H. <Astron. Astrophys. 609, A26 (2018)> =2018A&A...609A..26G (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, nearby ; Photometry, infrared Keywords: galaxies: structure - Galaxy: center - Galaxy: structure - infrared: stars Abstract: The existence of dynamically relaxed stellar density cusp in dense clusters around massive black holes is a long-standing prediction of stellar dynamics, but it has so far escaped unambiguous observational confirmation. In this paper we revisit the problem of inferring the innermost structure of the Milky Way's nuclear star cluster via star counts, to clarify whether it displays a core or a cusp around the central black hole. We use judiciously selected adaptive optics assisted high angular resolution images obtained with the NACO instrument at the ESO VLT. Through image stacking and improved PSF fitting we push the completeness limit about one magnitude deeper than in previous, comparable work. Crowding and extinction corrections are derived and applied to the surface density estimates. Known young, and therefore dynamically not relaxed stars, are excluded from the analysis. Contrary to previous work, we analyse the stellar density in well-defined magnitude ranges in order to be able to constrain stellar masses and ages. We conclude that the observed density of the faintest stars detectable with reasonable completeness at the Galactic Centre, is consistent with the existence of a stellar cusp around the Milky Way's central black hole, Sagittarius A*. Description: Photometric and astrometric parameters for the point source detections in the central parsec in the Galactic Centre. As we described in the manuscript, we work on four pointings which we do not combine to a final mosaic to avoid distortion issues. We analyse those four pointings in four different ways, applying different sets of StarFinder parameters. Therefore we present 16 tables, one for each pointing in the observations and StarFinder parameters. We present the extinction and completeness-corrected stellar density in three different magnitudes ranges. The tables are used to represent Figure 9 in the paper. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file pointings.pdf 512 1287 Images of the four pointings analyzed table1.dat 79 9237 *Galactic Centre stars. Pointing 1 and SF-set 1 table2.dat 79 7497 *Galactic Centre stars. Pointing 1 and SF-set 2 table3.dat 79 10551 *Galactic Centre stars. Pointing 1 and SF-set 3 table4.dat 79 8476 *Galactic Centre stars. Pointing 1 and SF-set 4 table5.dat 79 8201 *Galactic Centre stars. Pointing 2 and SF-set 1 table6.dat 79 6766 *Galactic Centre stars. Pointing 2 and SF-set 2 table7.dat 79 9321 *Galactic Centre stars. Pointing 2 and SF-set 3 table8.dat 79 7816 *Galactic Centre stars. Pointing 2 and SF-set 4 table9.dat 79 10023 *Galactic Centre stars. Pointing 3 and SF-set 1 table10.dat 79 8202 *Galactic Centre stars. Pointing 3 and SF-set 2 table11.dat 79 11217 *Galactic Centre stars. Pointing 3 and SF-set 3 table12.dat 79 9189 *Galactic Centre stars. Pointing 3 and SF-set 4 table13.dat 79 9457 *Galactic Centre stars. Pointing 4 and SF-set 1 table14.dat 79 7868 *Galactic Centre stars. Pointing 4 and SF-set 2 table15.dat 79 10698 *Galactic Centre stars. Pointing 4 and SF-set 3 table16.dat 79 8628 *Galactic Centre stars. Pointing 4 and SF-set 4 tablea1.dat 29 43 *Surface density for brighter stars tablea2.dat 29 43 *Surface density for faint stars tablea3.dat 29 43 *Surface density for fainter stars
Note on table1.dat table5.dat table9.dat table13.dat: The StarFinder (SF) parameter set 1 corresponds to min_correlation=0.80 and deblend=0 for all the pointings. Note on table2.dat table6.dat table10.dat table14.dat: The StarFinder (SF) parameter set 2 corresponds to min_correlation=0.85 and deblend=0 for all the pointings. Note on table3.dat table7.dat table11.dat table15.dat: The StarFinder (SF) parameter set 3 corresponds to min_correlation=0.85 and deblend=1 for all the pointings. Note on table4.dat table8.dat table12.dat table16.dat: The StarFinder (SF) parameter set 4 corresponds to min_correlation=0.90 and deblend=1 for all the pointings. Note on tablea1.dat: Surface density for stars in the magnitude interval 12.5 ≤ Ks ≤ 16.0. We exclude all spectroscopically identified early-type, i.e. young and massive, stars from our sample (using the data of Do et al. (2009ApJ...703.1323D, Cat. J/ApJ/703/1323) Note on tablea2.dat: Surface density for stars in the magnitude interval 16.5 ≤ Ks ≤ 17.5. We exclude all spectroscopically identified early-type, i.e. young and massive, stars from our sample (using the data of Do et al. (2009ApJ...703.1323D, Cat. J/ApJ/703/1323) Note on tablea3.dat: Surface density for stars in the magnitude interval 17.5 ≤ Ks ≤ 18.5. We exclude all spectroscopically identified early-type, i.e. young and massive, stars from our sample (using the data of Do et al. (2009ApJ...703.1323D, Cat. J/ApJ/703/1323)
See also: J/ApJ/703/1323 : Spectroscopy of stars in Galaxy's nuclear cluster (Do+ 2009) J/A+A/511/A18 : NIR observations of stars near SgrA* (Schoedel+, 2010) Byte-by-byte Description of file: table?.dat table1?.dat
Bytes Format Units Label Explanations
1- 7 F7.3 arcsec offX X position offset(increasing to the East) (1) 9- 15 F7.3 arcsec offY Y position offset (1) 17- 21 F5.3 arcsec e_offX Uncertainty on X position (2) 23- 27 F5.3 arcsec e_offY Uncertainty on Y position (2) 29- 34 F6.3 mag Ksmag Ks-band magnitude (3) 36- 40 F5.3 mag e_Ksmag Uncertainty on Ks-band magnitude (2) 42- 47 F6.3 mag Hmag ?=0 H-band magnitude (3) 49- 53 F5.3 mag e_Hmag ?=0 Uncertainty on H-band magnitude (2) 55- 59 F5.3 mag AK Extinction in the Ks band (4) 61- 65 F5.3 mag e_AK Uncertainty on extinction in the Ks band 67- 71 F5.3 % p Percentage reduction in observed stars(5) 73- 77 F5.3 mag comp Source detection completeness in the Ks-images 79 I1 --- ageFlag [0,1] Age Flag (0: old star, 1: young star) (6)
Note (1): Offset is from Sagittarius A*: tables 1-4 : Pointing 1: x0= 672 and y0=1448 tables 5-8 : Pointing 2: x0= 671 and y0= 431 tables 9-12 : Pointing 3: x0=1692 and y0= 425 tables 13-16 : Pointing 4: x0=1694 and y0=1446 Note (2): Uncertainties on positions and magnitudes are the formal uncertainties from StarFinder. Note (3): The photometry was calibrated with the stars IRS 16C, IRS 16NW, and IRS 33N. See Schoedel et al. (2010A&A...511A..18S, Cat. J/A+A/511/A18) Note (4): The extinction maps for each of the four pointings were created with the same method as applied in Schoedel et al. (2010A&A...511A..18S, Cat. J/A+A/511/A18) Note (5): Correction factor that we apply to each detected star to correct the individual stellar magnitudes for differential extinction by applying the methodology of Chatzopoulos et al. (2015MNRAS.453..939C) Note (6): We use the list of spectroscopically identified young stars from Do et al. (2009ApJ...703.1323D, Cat. J/ApJ/703/1323)
Byte-by-byte Description of file: tablea1.dat tablea2.dat tablea3.dat
Bytes Format Units Label Explanations
1- 9 F9.6 arcsec Rad Projected radius from Saggitarius A* 11- 19 F9.6 arcsec-2 Den Number stellar density for late-type stars 21- 29 F9.6 arcsec-2 e_Den Uncertainty on number stellar density
Acknowledgements: The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP7/2007-2013) / ERC grant agreement n<BA> [614922]. This work is based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programmes IDs 183.B-0100 and 089.B-0162. Eulalia Gallego Cano, lgc(at)iaa.es
(End) Eulalia Gallego Cano [IAA-CSIC, Spain], Patricia Vannier [CDS] 15-Sep-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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