J/A+A/352/228 Transitional YSOs candidates (Magnier+, 1999)
Transitional YSOs: candidates from flat-spectrum IRAS sources
Magnier E.A., Volp A.W., Laan K., Van den Ancker M.E., Waters L.B.F.M.
<Astron. Astrophys. 352, 228 (1999)>
=1999A&A...352..228M 1999A&A...352..228M
ADC_Keywords: YSOs ; Infrared sources
Keywords: stars: circumstellar matter - stars: evolution - stars: formation -
stars: mass-loss - stars: pre-main sequence
Abstract:
We are searching for Young Stellar Objects (YSOs) near the boundary
between protostars and pre-main-sequence objects, what we term
Transitional YSOs. We have identified a sample of 125 objects as
candidate transitional YSOs on the basis of IRAS colors and the
optical appearance on POSS plates. We have obtained optical and
near-IR imaging of 82 objects accessible from the Northern Hemisphere
and optical images of 62 sources accessible from the South. We also
created deconvolved 60µm IRAS images of all sources. We have
classified the objects on the basis of their morphology in the optical
and near-IR images. We find that the majority of our objects are
associated with star-forming regions, confirming our expectation that
the bulk of these objects are YSOs. Of the 125 objects, 28 have a
variety of characteristics very similar to other transitional YSOs,
while another 22 show some of these characteristics. Furthermore we
have found seven objects to be good candidates for members of the
Herbig Ae/Be stellar group, of which three are newly identified as
such.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 117 125 Transitional YSO candidate IRAS sources
table1.tex 236 179 LaTeX version of table1
table1.ps 72 871 PostScript version of table1
south/* . 62 *Poscript Figures for Southern observations
north/* . 83 *Poscript Figures for Northern observations
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Note on north/* and south/*: Northern and Southern observations have been
performed by two individual teams, and 23 sources have a figure
in the two subdirectories.
3 objects, IRAS 10075-6647, IRAS 10292-4148 and IRAS 19111+0212
have no figures.
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See also:
II/125 : IRAS catalogue of Point Sources, Version 2.0 (IPAC 1986)
J/ApJ/397/520 : IRAS obs. of YSO in Corona Australis (Wilking+, 1992)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- IRAS IRAS designation (NNNNN+NNNN)
12- 13 I2 h RAh Right ascension (J2000)
15- 16 I2 min RAm Right ascension (J2000)
18- 21 F4.1 s RAs Right ascension (J2000)
23 A1 --- DE- Declination sign (J2000)
24- 25 I2 deg DEd Declination (J2000)
27- 28 I2 arcmin DEm Declination (J2000)
30- 31 I2 arcsec DEs Declination (J2000)
33 I1 --- ID [1/7] Category (1)
35- 45 A11 --- southFile Name of postscript file, in "south" subdirectory
46 A1 --- Missing [*] files not present
47- 53 A7 --- northFile Name of postscript file, in "north" subdirectory
55-117 A63 --- Note Notes
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Note (1): The category number takes the following values:
1: A likely transitional YSO: A single moderately-bright, very-red
stellar object with extensive associated reflection nebulosity.
(28 objects)
2: A possible transitional YSO: a moderately red stellar object with
weak nebulosity or a significantly red object with no nebulosity.
(22 objects)
3: A YSO group: Several very red objects, usually with extended
nebulosity. No single object stands out. (21 objects)
4: Bright star. (7 objects)
5: A cluster of stars: usually a red cluster with no single very red
star. (18 objects)
6: A galaxy. (11 objects)
7: nothing: no object stands out, and no object can be associated with
any of the other classes. (18 objects)
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Acknowledgements: Arjan Volp
(End) Patricia Bauer [CDS] 28-Jan-2000