J/A+A/463/275 Chandra obs. of Serpens star-forming region (Giardino+, 2007)
The onset of X-ray emission in young stellar objects.
A Chandra observation of the Serpens star-forming region.
Giardino G., Favata F., Micela G., Sciortino S., Winston E.
<Astron. Astrophys., 463, 275-288 (2007)>
=2007A&A...463..275G 2007A&A...463..275G
ADC_Keywords: Associations, stellar ; YSOs ; Stars, pre-main sequence ;
X-ray sources
Keywords: ISM: clouds - ISM: individual objects: Serpens cloud -
stars: pre-main sequence - X-rays: stars
Abstract:
To study the properties of X-ray emission from young stellar objects
(YSOs) through their evolution from Class I to Class III and determine
whether Class 0 protostars emit X-rays.
A deep Chandra X-ray observation of the Serpens star-forming region
was obtained. The Serpens Cloud Core is ideally suited for this type
of investigation, being populated by a dense and extremely young
cluster whose members are found in all evolutionary stages, including
six well-studied Class 0 sources.
Description:
The core of the Serpens cloud was observed with Chandra starting at
21:43 UT on June 19, 2004. The observation lasted for 91.4ks
(although the scheduled duration was 100ks).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 95 85 X-ray sources detected with PWDETECT in the
Chandra observation of the Serpens star
forming region.
table6.dat 107 51 The cross-identification of the sources below
was obtained from the Simbad database,
with a search radius of 5 arcsec.
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See also:
I/252 : The USNO-A2.0 Catalogue (Monet+ 1998)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- [GFM2007] Sequential number
3 A1 --- n_[GFM2007] [*] *: sources associated with the elongated
PSF of source 48 (SVS 20)
5- 6 I2 h RAh Right ascension (J2000)
8- 9 I2 min RAm Right ascension (J2000)
11- 14 F4.1 s RAs Right ascension (J2000)
16 A1 --- DE- Declination sign (J2000)
17- 18 I2 deg DEd Declination (J2000)
20- 21 I2 arcmin DEm Declination (J2000)
23- 24 I2 arcsec DEs Declination (J2000)
26- 30 F5.2 ct/ks CR Count Rate
32- 35 F4.2 ct/ks e_CR rms uncertainty on CR
37- 40 F4.1 mag Jmag ?=- 2MASS counterpart J magnitude (1)
42- 45 F4.1 mag Hmag ?=- 2MASS counterpart H magnitude (1)
47- 50 F4.1 mag Kmag ?=- 2MASS counterpart K magnitude (1)
52- 54 F3.1 arcsec r ?=- radial distance from the 2MASS
counterpart (1)
56 A1 --- Opt [UT0-] Associations with (T)ycho 2 (I/259) or
(U)SNO-A2 (I/252) optical catalog sources (1)
58- 61 F4.1 mag Bmag ?=- B magnitude (1)
63- 66 F4.1 mag V/Rmag ?=- Tycho2 V magnitude or
USNOA-2.0 R magnitude (1)
68- 70 I3 --- ISO ?=- ISO number, [KOB2004] NNN in Simbad (2)
71 A1 --- n_ISO [*] *: distance of ISO source greater than 3"
73- 76 A4 --- clISO ISO classification (2) (4)
78- 82 I5 --- IRsrc ?=- Spitzer IR source number (3)
83 A1 --- u_IRsrc [)] Uncertaitny flag on IRsrc (5)
84 A1 --- n_IRsrc [+] +: matching distance >1" (5)
86- 88 I3 --- YSO ?=- Spitzer YSO number (3)
90- 95 A6 --- clYSO YSO classification (3) (4)
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Note (1): For the sources with a 2MASS counterpart (within a search radius
of 3 arcsec) the values of their magnitude in the J, H and K bands are
also given, together with the radial distance from this counterpart,
the associations with Tycho 2 or USNOA-2.0 optical catalog sources and
their optical magnitude.
Note (2): The ISO field provides the source number and Class of the
counterpart in the ISO catalogue by Kaas et al. (2004, Cat.
J/A+A/421/623), also within a search radius of 3".
Note (3): Source identification numbers and classification in the Spitzer
data: the first id is the source IR id and the second one the YSO id
number.
Note (4): Classes of the Young Stellar Object as follows:
I = Sources with a slope greater than 0
I/II = Flat Spectrum object (slope between 0.0 and -0.5)
II = Sources that show excess emission from a circumstellar disk,
with a slope between -0.5 and ~-3.5
II/III = Transition Disk object
III = source exhibits photospheric emission, with slopes of ~-3.5
Note (5): All the counterparts are within 1" from the X-ray sources,
unless their IR id is accompanied by + or is in between brackets.
+ = Although the matching distance is greater than 1", we are
confident in the cross-identification reliability
) = some doubts remains (these are usually faint IR sources).
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- [GFM2007] Sequential number
4- 5 I2 h RAh Right ascension (J2000)
7- 8 I2 min RAm Right ascension (J2000)
10- 13 F4.1 s RAs Right ascension (J2000)
15 A1 --- DE- Declination sign (J2000)
16- 17 I2 deg DEd Declination (J2000)
19- 20 I2 arcmin DEm Declination (J2000)
22- 23 I2 arcsec DEs Declination (J2000)
26-107 A82 --- CrossId Cross-identifications (1)
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Note (1): The acronyms are:
[B96] = Bontemps (1996, Ph.D. Thesis)
[CK86] = Churchwell & Koornneef (1986ApJ...300..729C 1986ApJ...300..729C, CK NN)
[EC92] = Eiroa & Casali (1992A&A...262..468E 1992A&A...262..468E)
[GCN98] = Giovannetti et al. (1998, Cat. J/A+A/330/990, GCNM NNN)
[HB96] = Hurt & Barsony (1996ApJ...460L..45H 1996ApJ...460L..45H, [HB96] PS N )
[KOB2004] = Kaas et al. (2004, Cat. J/A+A/421/621)
[KCM2004] = Klotz et al. (2004, Cat. J/A+A/425/927)
[P2003] = Preibisch (2003A&A...410..951P 2003A&A...410..951P)
[SVS76] = Strom, Vrba & Strom (1976AJ.....81..638S 1976AJ.....81..638S,
[SVS76] NGC 7129 & NN [SVS76] Ser NN).
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 21-Sep-2007