J/AJ/122/866 X-ray sources in IC 348 from Chandra (Preibisch+, 2001)
Deep Chandra X-ray observatory imaging study of the
very young stellar cluster IC 348.
Preibisch T., Zinnecker H.
<Astron. J. 122, 866 (2001)>
=2001AJ....122..866P 2001AJ....122..866P
ADC_Keywords: Clusters, open ; X-ray sources
Mission_Name: Chandra
Keywords: open clusters and associations: individual (IC 348) - stars: coronae -
stars: low-mass, brown dwarfs - stars: pre-main-sequence - X-rays
Abstract:
We have obtained a deep (53 ks) X-ray image of the very young stellar
cluster IC 348 with the Advanced CCD Imaging Spectrometer on board the
Chandra X-Ray Observatory. In our image with a sensitivity limit of
∼1x1028ergs/s (more than 10 times deeper than our ROSAT images of IC
348), 215 X-ray sources are detected. While 115 of these sources can
be identified with known cluster members, 58 X-ray sources are most
likely new, still unidentified cluster members. About 80% of all known
cluster members with masses between ∼0.15 and 2M☉ are visible as
X-ray sources in our image. We discover X-ray emission at levels of
∼1028ergs/s from four of 13 known brown dwarfs and from three of 12
brown dwarf candidates in IC 348. We also detect X-ray emission from
two deeply embedded objects, presumably class I protostars, south of
the cluster center. Description:
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 51 215 ACIS X-ray Sources in IC 348
table2.dat 104 25 Brown dwarfs and brown dwarfs candidates in IC 348
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See also:
J/A+A/324/549 : Deep UVBRI photometry in IC 348 (Trullols+ 1997)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- CXOPZ Source number
6 I1 h RAh Right Ascension (J2000)
8- 9 I2 min RAm Right Ascension (J2000)
11- 15 F5.2 s RAs Right Ascension (J2000)
17 A1 --- DE- Declination sign (J2000)
18- 19 I2 deg DEd Declination (J2000)
21- 22 I2 arcmin DEm Declination (J2000)
24- 27 F4.1 arcsec DEs Declination (J2000)
30- 33 F4.1 arcsec e_RAs Right Ascension position uncertainty
35- 38 F4.1 arcsec e_DEs Declination position uncertainty
41- 45 F5.2 ct/ks CR Count rate
48- 51 F4.2 ct/ks e_CR Error in CR
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- Origin L99: Objects from Luhman, 1999ApJ...525..466L 1999ApJ...525..466L
N00: Additional objects from Najita et al.,
2000ApJ...541..977N 2000ApJ...541..977N
5- 10 A6 --- Object Object identification (1)
12- 17 A6 --- SpType Spectral type
18- 20 F3.1 --- e_SpType ? Uncertainty on sub-type
22- 24 A3 --- Class Classification (2)
27- 31 F5.2 mag AVmag Absorption in V band
32 A1 --- u_AVmag Uncertainty flag on AVmag
34- 39 F6.4 solLum Lbol Bolometric luminosity
41- 42 A2 --- l_Massl [~< ] Limit flag on Massl
43- 46 F4.2 solMass Massl Mass, lower limit (3)
49- 52 F4.2 solMass Massu ? Mass, upper limit (3)
54 A1 --- l_ACIS Limit flag on ACIS
55- 58 F4.1 ct ACIS Number of background-subtracted source
counts detected in the ACIS image
60- 62 F3.1 --- e_ACIS ? rms uncertainty on ACIS
64 A1 --- l_Lx Limit flag on Lx
65- 68 F4.1 10+21W Lx X-ray luminosity (4)
70- 72 F3.1 10+21W e_Lx ? rms uncertainty on Lx
74 A1 --- l_log(Lx/Lbol) Limit flag on log(Lx/Lbol)
75- 78 F4.1 --- log(Lx/Lbol) X-ray to bolometric luminosity ratio
81- 82 I2 h RAh Right ascension (J2000)
84- 85 I2 min RAm Right ascension (J2000)
87- 91 F5.2 s RAs Right ascension (J2000)
93 A1 --- DE- Declination sign (J2000)
94- 95 I2 deg DEd Declination (J2000)
97- 98 I2 arcmin DEm Declination (J2000)
100-103 F4.1 arcsec DEs Declination (J2000)
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Note (1): Luhman 1999: Cl* IC 348 LRL NNN in Simbad
Note (2): (BD) brown dwarf; (BDC) brown dwarf candidate.
Note (3): Range of the mass estimates given by the different models and
temperature scales.
Note (4): Dereddened 0.2-8 keV-band X-ray luminosity based on the exposure
time-corrected source count rate computed assuming a Raymond-Smith
plasma spectrum with kT=1keV.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 10-Sep-2001