J/A+A/453/535 Classification of bright mid-IR sources (Schuller+, 2006)
Recent star formation in the inner Galactic Bulge seen by ISOGAL.
I. Classification of bright mid-IR sources in a test field.
Schuller F., Omont A., Glass I.S., Schultheis M., Egan M.P., Price S.D.
<Astron. Astrophys. 453, 535 (2006)>
=2006A&A...453..535S 2006A&A...453..535S
ADC_Keywords: Infrared sources - Stars, variable - Photometry, infrared
Keywords: Galaxy: Centre - Stars: formation - Stars: variables: general -
Infrared: stars
Abstract:
Context: The stellar populations in the central region of the Galaxy
are poorly known because of the high visual extinction and very great
source density in this direction.
Aims: To use recent infrared surveys for studying the dusty stellar
objects in this region.
Methods: We analyse the content of a ∼20x20arcmin^2 field centred at
(l,b)=(-0.27,-0.06) observed at 7 and 15 microns as part of the
ISOGAL survey. These ISO observations are more than an order of
magnitude better in sensitivity and spatial resolution than the IRAS
observations. The sources are cross-associated with other catalogues
to identify various types of objects. We then derive criteria to
distinguish young objects from post-main sequence stars.
Results: We find that a sample of about 50 young stellar objects and
ultra-compact HII regions emerges, out of a population of evolved AGB
stars. We demonstrate that the sources colours and spatial extents, as
they appear in the ISOGAL catalogue, possibly complemented with MSX
photometry at 21 microns, can be used to determine whether the ISOGAL
sources brighter than 300mJy at 15 microns (or [15]<4.5mag) are
young objects or late-type evolved stars.
Description:
The photometry of the 46 candidate young objects that we have selected
is given in this table. It includes ISO photometry at 7 and 15
microns, as well as complementary data from near-infrared surveys
(DENIS, 2MASS) and mid- to far-infrared surveys (MSX, IRAS).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 193 46 Magnitudes of the selected candidate young objects
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See also:
II/243 : The ISOGAL Point Source Catalogue - IGPSC (Omont+ 2003)
V/114 : MSX6C Infrared Point Source Catalog (Egan+ 2003)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
B/denis : The DENIS database (DENIS Consortium, 2005)
II/125 : IRAS catalogue of Point Sources, Version 2.0 (IPAC 1986)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- ISOGAL-PJ Name (ISOGAL-P Jhhmmss.s+ddmmss)
17- 22 F6.3 mag J2mag ?=99.99 2MASS J magnitude
24- 29 F6.3 mag H2mag ?=99.99 2MASS H magnitude
31- 36 F6.3 mag K2mag ?=99.99 2MASS K magnitude
38 A1 --- q_J2mag 2MASS flag (1)
39 A1 --- q_H2mag 2MASS flag (1)
40 A1 --- q_K2mag 2MASS flag (1)
42- 45 F4.2 arcsec d2MASS ISO-2MASS separation
47- 51 F5.2 mag Imag ?=99.99 DENIS I magnitude
53- 57 F5.2 mag Jmag ?=99.99 DENIS J magnitude
59- 63 F5.2 mag Kmag ?=99.99 DENIS K magnitude
65- 68 F4.2 arcsec dDENIS ?=0.00 ISO-DENIS separation
70- 75 F6.3 Jy S7um ISO 7 microns flux density (PSF fit)
77- 82 F6.3 Jy S15um ISO 15 microns flux density (PSF fit)
84- 88 F5.2 Jy S15umap ISO 15 microns flux density (aperture)
90- 94 F5.3 Jy e_S15um Uncertainty on ISO 15 microns flux density
96 I1 --- q_S7um ISOGAL quality flag (2)
97 I1 --- q_S15um ISOGAL quality flag (2)
99-102 F4.2 arcsec d7-15um ?=0.00 7-15 microns separation
104-120 A17 --- MSX MSX6C source name
122-127 F6.2 Jy SMSXA ? MSX A-band flux density
129-134 F6.2 Jy SMSXC ? MSX C-band flux density
136-141 F6.2 Jy SMSXD ? MSX D-band flux density
143-148 F6.2 Jy SMSXE ? MSX E-band flux density
150 I1 --- q_SMSXA ? MSX quality flag (3)
151 I1 --- q_SMSXC ? MSX quality flag (3)
152 I1 --- q_SMSXD ? MSX quality flag (3)
153 I1 --- q_SMSXE ? MSX quality flag (3)
155-158 F4.1 arcsec dMSX ? ISO-MSX separation
160-169 A10 --- IRAS IRAS source name
171-174 F4.1 Jy S12um ? IRAS 12 microns flux density
176-178 I3 Jy S25um ? IRAS 25 microns flux density
180-183 I4 Jy S60um ? IRAS 60 microns flux density
185-188 I4 Jy S100um ? IRAS 100 microns flux density
190 I1 --- q_S12um ? IRAS quality flag (4)
191 I1 --- q_S25um ? IRAS quality flag (4)
192 I1 --- q_S60um ? IRAS quality flag (4)
193 I1 --- q_S100um ? IRAS quality flag (4)
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Note (1): 2MASS quality flags. See catalog II/246 for a full description.
Most common flags are "U" for upper-limit, and "A", "B" or "C"
for detection with signal-to-noise ratio above 5.
Note (2): ISOGAL quality flags. See the ISOGAL-PSC Explanatory Supplement
(2003A&A...403..955S 2003A&A...403..955S, Cat. II/243) for full description.
Note (3): MSX quality flags. See catalog V/114 for a full description.
0 means non-detection, 4 is best quality.
Note (4): IRAS quality flags. 1 means upper limit, 3 is best quality.
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Acknowledgements:
Frederic Schuller, schuller(at)mpifr-bonn.mpg.de
(End) Frederic Schuller [MPIfR, Germany], Patricia Vannier [CDS] 20-Jun-2006