J/ApJ/654/347 Chandra X-ray observations in Eagle Nebula. I. (Linsky+, 2007)
Chandra observations of the Eagle nebula.
I. Embedded young stellar objects near the pillars of creation.
Linsky J.L., Gagne M., Mytyk A., Mccaughrean M., Andersen M.
<Astrophys. J., 654, 347-360 (2007)>
=2007ApJ...654..347L 2007ApJ...654..347L
ADC_Keywords: Clusters, open ; X-ray sources
Keywords: ISM: individual (HH 216) - open clusters and associations:
individual (Eagle Nebula, M16, NGC 6611) - stars: activity -
stars: coronae - stars: early-type - stars: pre-main-sequence -
X-rays: stars
Abstract:
We present and analyze the first high-resolution X-ray images ever
obtained of the Eagle Nebula star-forming region. On 2001 July 30 the
Chandra X-Ray Observatory obtained a 78ks image of the Eagle Nebula
(M16) that includes the core of the young galactic cluster NGC 6611
and the dark columns of dust and cold molecular gas in M16 known as
the "Pillars of Creation". We find a total of 1101 X-ray sources in
the 17'x17' ACIS-I field of view. Most of the X-ray sources are
low-mass pre-main-sequence or high-mass main-sequence stars in this
young cluster. A handful of hard X-ray sources in the pillars are
spatially coincident with deeply embedded young stellar objects seen
in high-resolution near-infrared images recently obtained with the VLT
(McCaughrean & Andersen, 2002A&A...389..513M 2002A&A...389..513M). In this paper, we focus
on the 40 X-ray sources in and around pillars 14 at the heart of the
Eagle Nebula. None of the X-ray sources are associated with the
evaporating gaseous globules (EGGs) first observed by Hester and
coworkers) in HST WFPC2 images of M16, implying either that the EGGs
do not contain protostars or that the protostars have not yet become
X-ray active. Eight X-ray counts are coincident with the Herbig-Haro
object HH 216, implying logLX∼30.0.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 77 40 Chandra X-Ray Sources in M16: WFPC2 Field
table2.dat 148 41 *Optical and Near-Infrared Counterparts:
WFPC2 Field
table3.dat 94 40 Chandra Sources in M16:
Sugitani et al. (2002ApJ...565L..25S 2002ApJ...565L..25S) Matches
--------------------------------------------------------------------------------
Note on table2.dat: Comparable data for the entire Chandra field (1161
records) will be available in machine readable format in Paper II.
Entries with no data in column (2) have the same designation as the
source in the previous row. This X-ray source has two or more
candidate near-infrared counterparts.
--------------------------------------------------------------------------------
See also:
B/chandra : The Chandra Archive Log (CXC, 1999-)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- [LGM2007] Source number
5- 20 A16 --- Name X-ray source name (JHHMMSS.s+DDMMSS)
22- 23 I2 h RAh Right ascension (J2000.0)
25- 26 I2 min RAm Right ascension (J2000.0)
28- 32 F5.2 s RAs Right ascension (J2000.0)
34 A1 --- DE- Declination sign (J2000.0)
35- 36 I2 deg DEd Declination (J2000.0)
38- 39 I2 arcmin DEm Declination (J2000.0)
41- 44 F4.1 arcsec DEs Declination (J2000.0)
46- 48 I3 ct Rct Raw counts
50- 54 F5.1 ct Nct Net counts
56- 59 F4.1 ct e_Nct rms uncertainty on Nct
61- 65 F5.1 10-19W/m2 fX 0.5-7.0keV X-ray flux in 10-16arg/cm2/s
(not corrected for absorption)
67- 70 F4.2 --- K-S K-S time variability statistic
72- 75 F4.2 keV Emed Mean photon energy
77 A1 --- T3 [*] * indicates Sugitani matches
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- [LGM2007] Source number
5- 20 A16 --- Name X-ray source name (JHHMMSS.s+DDMMSS)
22- 23 I2 h RAh ? VLT Right ascension (J2000.0)
25- 26 I2 min RAm ? VLT Right ascension (J2000.0)
28- 32 F5.2 s RAs ? VLT Right ascension (J2000.0)
34 A1 --- DE- ? VLT Declination sign (J2000.0)
35- 36 I2 deg DEd ? VLT Declination (J2000.0)
38- 39 I2 arcmin DEm ? VLT Declination (J2000.0)
41- 44 F4.1 arcsec DEs ? VLT Declination (J2000.0)
46- 49 F4.2 arcsec OVLT ? Offset with VLT source
51- 55 F5.2 mag Jsmag ? VLT Js magnitude
57- 61 F5.2 mag Hmag ? VLT H magnitude
65- 69 F5.2 mag Ksmag ? VLT Ks magnitude
71- 72 I2 h RA2h ? 2MASS Right ascension (J2000.0)
74- 75 I2 min RA2m ? 2MASS Right ascension (J2000.0)
77- 81 F5.2 s RA2s ? 2MASS Right ascension (J2000.0)
83 A1 --- DE2- ? 2MASS Declination sign (J2000.0)
84- 85 I2 deg DE2d ? 2MASS Declination (J2000.0)
87- 88 I2 arcmin DE2m ? 2MASS Declination (J2000.0)
90- 93 F4.1 arcsec DE2s ? 2MASS Declination (J2000.0)
95- 98 F4.2 arcsec O2M ? Offset with 2MASS source
100-104 F5.2 mag J2mag ? 2MASS J magnitude
106-110 F5.2 mag H2mag ? 2MASS H magnitude
112-116 F5.2 mag Ks2mag ? 2MASS Ks magnitude
118-120 I3 --- Walk ? Walker number, 1961ApJ...133..438W 1961ApJ...133..438W,
NGC 6611 NNN
122-126 I5 --- BKP ? Belikov number, 1999, Cat. J/A+AS/134/525,
Cl* NGC 6611 BKP NNNNN in Simbad
128-132 F5.2 mag Bmag ? B magnitude
134-138 F5.2 mag Vmag ? V magnitude
140-143 A4 --- SpT MK spectral type
145-148 F4.2 mag AV ? Absorption in V band
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- [LGM2007] Source number
5- 20 A16 --- Name Source name (JHHMMSS.s+DDMMSS)
22- 36 A15 --- Sug Sugitani et al. (2002ApJ...565L..25S 2002ApJ...565L..25S)
SN IRS designation (1)
37 A1 --- n_Sug [c] Note on Sug (2)
39- 42 F4.2 arcsec Offset Offset between positions
44- 48 F5.1 ct/s CR Net counts rate
50- 53 F4.2 --- K-S K-S time variability statistic
55- 58 F4.2 keV Emed Mean photon energy
60- 64 F5.1 10-19W/m2 fX Absorpbed 0.5-7.0keV X-ray flux
66- 70 F5.2 mag Jmag ?=- J magnitude
72- 76 F5.2 mag Hmag H magnitude
78- 82 F5.2 mag Ksmag Ks magnitude
84- 87 F4.1 mag AV ?=- Absorption in V band
89- 92 F4.1 10-7W logLX Unabsorbed 0.5-7keV luminosity assuming d=2kpc
94 A1 --- T1 [*] * indicates objects in WFPC2 field
--------------------------------------------------------------------------------
Note (1): For all sources but 3, the name is HHMMSS.s+DDMMSS.
* M16 ES-2 (T1) = [TSH2002] M16 ES-2 = [STN2002] T1 in Simbad
* M16 ES-1 (P1) = [TSH2002] M16 ES-1 = [STN2002] P1 in Simbad
Note (2): c = For the bright star BD-13 4930 photometry is from 2MASS, and
astrometry is from Hipparcos
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 25-Nov-2008