J/A+A/530/A150 XMM observations of λ Ori cluster (Franciosini+, 2011)
XMM-Newton observations of the young open cluster around λ Orionis.
Franciosini E., Sacco G.G.
<Astron. Astrophys., 530, A150 (2011)>
=2011A&A...530A.150F 2011A&A...530A.150F
ADC_Keywords: Clusters, open ; X-ray sources ; Photometry, UBVRI ;
Photometry, infrared
Keywords: open clusters and associations: individual: lambda Orionis -
stars: activity - stars: coronae - stars: late-type -
stars: pre-main sequence - X-rays: stars
Abstract:
We studied the X-ray properties of the young (∼1-8Myr) open cluster
around the hot (O8 III) star λ Ori and compared them with those
of the similarly-aged sigma Ori cluster to investigate possible
effects of the different ambient environment.
We analysed an XMM-Newton observation of the cluster using EPIC
imaging and low-resolution spectral data. We studied the variability
of detected sources, and performed a spectral analysis of the
brightest sources in the field using multi-temperature models.
Description:
The λ Ori cluster was observed by XMM-Newton from 20:46 UT on
September 28, 2006 to 12:23 UT on September 29, 2006 (Obs. ID
0402050101), for a total duration of 56ks, using both the EPIC MOS
and PN cameras and the RGS instruments. The EPIC cameras were operated
in full frame mode with the thick filter.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 101 169 X-ray sources detected in the λ Ori cluster
table1.dat 98 58 X-ray and optical properties of sources identified
with known cluster members and candidates
table2.dat 78 24 X-ray sources identified with possible new
cluster candidates
tablea2.dat 122 78 3σ upper limits and optical properties of
undetected cluster members and candidates
--------------------------------------------------------------------------------
See also:
J/AJ/118/2409 : VRI photometry of lambda Ori PMS stars (Dolan+, 1999)
J/AJ/123/387 : VRI photometry of lambda Ori star-forming region (Dolan+ 2002)
J/ApJ/610/1064 : lambda Ori substellar population (Barrado y Navascues+ 2004)
J/ApJ/664/481 : Collinder 69 optical/IR photometry (Barrado y Navascues+ 2007)
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- LOX Sequential number
5- 6 I2 h RAh X-ray right ascension (J2000)
8- 9 I2 min RAm X-ray right ascension (J2000)
11- 15 F5.2 s RAs X-ray right ascension (J2000)
17 A1 --- DE- X-ray declination sign (J2000)
18- 19 I2 deg DEd X-ray declination (J2000)
21- 22 I2 arcmin DEm X-ray declination (J2000)
24- 27 F4.1 arcsec DEs X-ray declination (J2000)
29- 33 F5.2 arcmin Offaxis Offaxis
35- 39 F5.1 --- Signi Detection significance
41- 46 F6.2 ct/ks CRate MOS-equivalent count rates in
the 0.3-7.8keV band
48- 51 F4.2 ct/ks e_CRate rms uncertainty on CRate
53- 75 A23 --- Ident Cross-dentification (G1)
76 A1 --- n_Ident [e] Binarity (2)
78- 81 F4.2 arcsec Offset ? Offset between X-ray source and
optical identification
83-101 A19 --- Memb Notes about membership (3)
--------------------------------------------------------------------------------
Note (2): This star has a fainter visual companion (2MASS J05340664+1001034,
J=13.10mag) at a distance of ∼5-arcsec, which however falls outside
our identification radius (offset=4.2-arcsec).
Note (3): Membership status:
Member = previously known members and candidates
NM = previously known non-members. Reason for membership exclusion
in parenthesis.
New? = possible new member candidate
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- LOX Sequential number
5- 27 A23 --- Ident Identification (G1)
29- 33 F5.2 [10-7W] logLX X-ray luminosity in the 0.3-8keV band
34 A1 --- n_logLX [*] * when derived from spectral fits
36- 40 F5.2 [-] logX/b X-ray-to-bolometric luminosity ratio
42- 46 F5.2 mag Vmag ?=- V magnitude
48- 52 F5.2 mag Rmag ?=- R magnitude
54- 58 F5.2 mag Imag ?=- I magnitude
60- 64 F5.2 mag Jmag ?=- J magnitude
66- 70 F5.2 mag Hmag ?=- H magnitude
72- 76 F5.2 mag Ksmag ?=- Ks magnitude
78- 82 F5.2 Msun Mass ?=- Mass
84- 88 A5 --- SpType MK spectral type
90- 96 A7 --- Disc Disc classification (G2)
98 A1 --- Mm [s] Membership code (G3)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- LOX Sequential number
5- 21 A17 --- 2MASS 2MASS name (JHHMMSSss+DDMMSSs)
23- 27 F5.2 mag Vmag ?=- V magnitude (1)
29- 33 F5.2 mag Rmag ?=- R magnitude (1)
34 A1 --- n_Rmag [*] Note on Rmag (1)
36- 40 F5.2 mag Imag ?=- I magnitude (1)
41 A1 --- n_Imag [*] Note on Imag (1)
43- 47 F5.2 mag Jmag ?=- J magnitude
49- 53 F5.2 mag Hmag ?=- H magnitude
55- 59 F5.2 mag Ksmag ?=- Ks magnitude
61- 65 F5.2 [10-7W] logLX X-ray luminosity in the 0.3-7.8keV band
assuming d=400pc
66 A1 --- n_logLX [*] * when derived from spectral fits
67 A1 --- f_logLX [d] d when X-ray luminosity has been equally
divided between the two stars (see text)
69- 73 F5.2 [-] logX/b X-ray-to-bolometric luminosity ratio (2)
75- 78 F4.2 Msun Mass ?=- Estimated mass (2)
--------------------------------------------------------------------------------
Note (1): Optical photometry from Dolan & Mathieu (2002, Cat. J/AJ/123/387),
except for the values marked with an asterisk that are photographic
magnitudes from the USNO-B1.0 or GSC2.3 catalogues.
Note (2): For stars with optical photometry, Lbol and masses were derived
from the optical colours; for the others, they were computed from the
J or Ks magnitudes for an age of 5Myr.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- Ident Identification (G1)
25- 26 I2 h RAh Right ascension (J2000)
28- 29 I2 min RAm Right ascension (J2000)
31- 35 F5.2 s RAs Right ascension (J2000)
37 A1 --- DE- Declination sign (J2000)
38- 39 I2 deg DEd Declination (J2000)
41- 42 I2 arcmin DEm Declination (J2000)
44- 47 F4.1 arcsec DEs Declination (J2000)
49 A1 --- l_CRate Limit flag on CRate
50- 54 F5.2 ct/ks CRate MOS-equivalent count rates in
the 0.3-7.8keV band upper limit (1)
56 A1 --- l_logLX Limit flag on logLX
57- 61 F5.2 [10-7W] logLX X-ray luminosity in the 0.3-8keV band
(upper limit)
63 A1 --- l_logX/b Limit flag on logX/b
64- 68 F5.2 [-] logX/b X-ray-to-bolometric luminosity ratio
(upper limit)
70- 74 F5.2 mag Vmag ?=- V magnitude
76- 80 F5.2 mag Rmag ?=- R magnitude
82- 86 F5.2 mag Imag ?=- I magnitude
88- 92 F5.2 mag Jmag ?=- J magnitude
94- 98 F5.2 mag Hmag ?=- H magnitude
100-104 F5.2 mag Ksmag ?=- Ks magnitude
106-109 F4.2 Msun Mass ?=- Mass
111-115 A5 --- SpType MK spectral type
117-120 A4 --- Disc Disc classification (G2)
122 A1 --- Mm [s] Membership code (G3)
--------------------------------------------------------------------------------
Note (1): Upper limits higher than 2ct/ks are overestimated due to close
bright sources.
--------------------------------------------------------------------------------
Global notes:
Note (G1): Remarks about the identifications:
* Identifications labelled DM refer to Dolan & Mathieu (1999, Cat.
J/AJ/118/2409, <[DM99] NN> in Simbad),
* Identifications labelled LOri refer to Barrado y Navascues et al.
(2004, Cat. J/ApJ/610/1064, <LOri-CFHT NNN> in Simbad),
* Identifications labelled Lori-SOC refer to Bouy et al.
(2009A&A...504..199B 2009A&A...504..199B, <LOri-SOC NN> in Simbad)
* In table1.dat and tablea1.dat, 2MASS J05340691+1001005 (LOX 1)
and J05351974+0947476 (LOX 99) are stars X2 and X4 from Stone & Taam
(1985ApJ...291..183S 1985ApJ...291..183S).
* In table1.dat and tablea1.dat, the two stars with a TYC identification
are stars b and f in Murdin & Penston (1977MNRAS.181..657M 1977MNRAS.181..657M).
* In tablea2.dat, the GSC and 2MASS identifications correspond to the
stars labelled c, d, e, g, and Ton 72 in Murdin & Penston
(1977MNRAS.181..657M 1977MNRAS.181..657M), respectively.
Note (G2): Disc classification from Barrado y Navascues et al. (2007,
Cat. J/ApJ/664/481) and Hernandez et al. (2009ApJ...707..705H 2009ApJ...707..705H); for
class II or EV (stars with disk) we also indicate whether there is
spectroscopic evidence for accretion (a) or not (n).
Note (G3): An "s" in this column indicates spectroscopically-confirmed
members (i.e. objects with spectroscopic youth features and radial
velocity consistent with membership).
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 27-Sep-2011