J/A+A/392/971 Catalogue of bright YSO candidates in ISOGAL (Felli+, 2002)
Young massive stars in the ISOGAL survey. II.
The catalogue of bright YSO candidates.
Felli M., Testi L., Schuller F., Omont A.
<Astron. Astrophys. 392, 971 (2002)>
=2002A&A...392..971F 2002A&A...392..971F
ADC_Keywords: YSOs - Photometry, infrared
Keywords: stars: formation - HII regions - Galaxy: structure - infrared: star
Abstract:
The 7 and 15µm observations of selected fields in the Galactic
Plane obtained with ISOCAM during the ISOGAL program offer an unique
possibility to search for previously unknown YSOs, undetected by IRAS
because of lower sensitivity or confusion problems. In a previous
paper (Felli et al., 2000, Cat. J/A+A/362/199) we established
criteria of general validity to select YSOs from the much larger
population of Post Main Sequence (Post-MS) stars present in the ISOGAL
fields by comparing radio and IR observations of five fields located
at l∼45°. The selection was based primarily on the position of the
point sources in the [15]-([7]-[15]) diagram, which involves only
ISOGAL data and allows to find possible YSOs using the survey data
alone. In the present work we revise the adopted criteria by comparing
radio-identified ultra-compact HII regions and ISOGAL observations
over a much larger region. The main indications of the previous
analysis are confirmed, but the criteria for selecting YSO candidates
had to be revised to select only bright objects, in order to limit the
contamination of the sample by Post-MS stars. The revised criteria
([15]≤4.5, [7]-[15]≥1.8) are then used to extract YSO candidates
from the ISOGAL Point Source Catalogue in preparation. We select a
total of 715 YSO candidates, corresponding to ∼2 of the sources with
good detections at 7 and 15µm. The results are presented in a table
form that provides an unique input list of small diameter, ≤6",
Galactic YSO candidates. The global properties of the sample of YSO
candidates are briefly discussed.
Description:
Table of candidate YSOs extracted from the ISOGAL survey database. For
each source we report the ISOGAL name, the galactic coordinates
and the mid- and near-infrared photometry, based on the ISOGAL and
DENIS surveys. When found in the Becker et al. (1994, Cat.
J/ApJS/91/347), the name of the radio continuum counterpart is also
reported.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 108 715 YSO candidates in the ISOGAL survey
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See also:
B/iso : ISO Observation Log of validated data (ISO Data Centre, 2001)
B/denis : The DENIS database (Epchtein+, 1999)
J/A+A/362/199 : YSOs in the l=+45 ISOGAL field (Felli+, 2000)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- --- [ISOGAL-P]
9- 24 A16 --- Name ISOGAL source name (based on J2000 coordinates)
26- 33 F8.4 deg GLON [-46/139] Galactic longitude
36- 42 F7.4 deg GLAT Galactic latitude
44- 48 F5.2 mag [15] ISOGAL 15um magnitude
50- 54 F5.2 mag [7] ISOGAL 7um magnitude
56- 60 F5.2 mag Ksmag ? DENIS Ks magnitude (2.5um)
61 A1 --- f_Ksmag [SE] S=saturated, E=extended
62- 66 F5.2 mag Jmag ? DENIS J magnitude (1.25um)
67 A1 --- f_Jmag [SE] S=saturated, E=extended
68- 72 F5.2 mag Imag ? DENIS I magnitude (0.82um)
73 A1 --- f_Imag [SE] S=saturated, E=extended
74- 75 I2 --- Aid ISOGAL-DENIS association flag (1)
77- 78 I2 --- Sd DENIS YSO confidence flag (2)
80- 92 A13 --- Name5GHz Radio source name (LLL.lll+B.bbb,
Becker et al., 1994, Cat. J/ApJS/91/347)
94-107 A14 --- IGfield ISOGAL field designation
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Note (1): The ISOGAL-DENIS association flag is a measure of the reliability
of the association between the mid- and near-infrared source, a
complete discussion of this flag is given in (Schuller et al., 2002,
in prep.).
The flag is set to "-1" if the ISOGAL field has not been covered by
the DENIS survey.
Note (2): The DENIS YSO confidence flag offer an additional confidence
criterion for the nature of the candidate.
The value is "-1" if the source is outside the region observed by DENIS.
A complete description of this flag is given in Sect. 5 of the paper.
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Acknowledgements: Leonardo Testi
References:
Testi et al, Paper I 1999A&AS..138...71T 1999A&AS..138...71T
(End) Leonardo Testi [INAF-Arcetri, Italy], Patricia Bauer [CDS] 08-Jul-2002