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J/ApJ/562/446       X-rays and protostars in Trifid nebula         (Rho+, 2001)

X-rays and protostars in the Trifid nebula. Rho J., Corcoran M.F., Chu Y.-H., Reach W.T. <Astrophys. J. 562, 446 (2001)> =2001ApJ...562..446R
ADC_Keywords: H II regions ; X-ray sources ; YSOs ; Stars, pre-main sequence Keywords: H II regions - infrared: stars - stars: formation - X-rays: individual (Trifid Nebula) Abstract: The Trifid Nebula is a young HII region, recently rediscovered as a "pre-Orion" star-forming region, containing protostars undergoing violent mass ejections visible in optical jets as seen in images from the Infrared Space Observatory and the Hubble Space Telescope. We report the first X-ray observations of the Trifid Nebula using ROSAT and ASCA. The ROSAT image shows a dozen X-ray sources, with the brightest X-ray source being the O7 star, HD 164492, which provides most of the ionization in the nebula. We also identify 85 T Tauri star and young, massive star candidates from near-infrared colors using the JHKs color-color diagram from the Two-Micron All-Sky Survey (2MASS). Ten X-ray sources have counterpart near-infrared sources. The 2MASS stars and X-ray sources suggest there are potentially numerous protostars in the young HII region of the Trifid. ASCA moderate-resolution spectroscopy of the brightest source shows hard emission up to 10keV with a clearly detected FeK line. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table13.dat 132 13 List of the 12 sources detected in the PSPC Image of the Trifid nebula and infrared counterparts table2.dat 29 85 2MASS young stellar object and T Tauri star candidates in the Trifid nebula
See also: B/2mass : The 2MASS database (IPAC/UMass, 2000) Byte-by-byte Description of file: table13.dat
Bytes Format Units Label Explanations
1- 3 A3 --- --- [RXT] 5- 6 I2 --- RXT RXT designation 8- 9 I2 h RAh Right ascension (J2000.0) 11- 12 I2 min RAm Right ascension (J2000.0) 14- 18 F5.2 s RAs Right ascension (J2000.0) 20 A1 --- DE- Declination sign (J2000.0) 21- 22 I2 deg DEd Declination (J2000.0) 24- 25 I2 arcmin DEm Declination (J2000.0) 27- 30 F4.1 arcsec DEs Declination (J2000.0) 32- 37 F6.4 ct/s CR Count Rate 39- 44 F6.4 ct/s e_CR rms uncertainty on CR 46- 48 F3.1 ---- Det Detection (1σ) 50- 54 F5.2 [10-10W/m2] logLX ? X-ray luminosity 56 A1 --- Note [ab] Individual notes (1) 58- 61 A4 --- Type Type of the 2MASS counterparts (2) 63- 66 F4.1 arcsec dproj ? Projected distance between the X-ray and 2MASS sources 68- 69 I2 h RA2h ? 2MASS counterpart right ascension (J2000) 71- 72 I2 min RA2m ? 2MASS counterpart right ascension (J2000) 74- 77 F4.1 s RA2s ? 2MASS counterpart right ascension (J2000) 79 A1 --- DE2- 2MASS counterpart declination sign (J2000) 80- 81 I2 deg DE2d ? 2MASS counterpart declination (J2000) 83- 84 I2 arcmin DE2m ? 2MASS counterpart declination (J2000) 86- 89 F4.1 arcsec DE2s ? 2MASS counterpart Declination (J2000) 91- 95 F5.2 mag Jmag ? 2MASS counterpart J magnitude 97-101 F5.2 mag Hmag ? 2MASS counterpart H magnitude 103-107 F5.2 mag Ksmag ? 2MASS counterpart Ks magnitude 109-132 A24 --- Com Comments (3)
Note (1): Individual notes as follows: a = RXT 8 is HD 164492 (O7 star) and/or YSO (TC1 in Cernicharo et al., 1998Sci...282..462C), and see table4 for Spectral Fit Results b = RXT 11 also coincides with HD 313596 (B8 star) Note (2): Notes for the 2MASS sources as follows: TTS = T Tauri star YSO = massive young stellar object red = red 2MASS star Mult = Multiple Note (3): In the comments: J="fill": the J-band photometry is measured in band-filled within the aperture, indicating their photometric uncertainties are large. High psf Δχ2: the goodness of the fit of a point-spread function is high, indicating the sources are either extended or unresolved double sources.
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 6 A6 --- [RCC2001] Object name (YSO NN or TTS NN) 8- 29 A22 --- 2MASS 2MASS designation (1)
Note (1): 2MASSI and 2MASSW indicate the Incremental Release and Working Database catalogs, respectively.
Table 4: Spectral Fit Results from Simultaneous Fit Using ASCA/PSPC -------------------------------------------------------------------------------- Parameters Trifid -------------------------------------------------------------------------------- ISM NH (1021cm-2) ∼3 T2 3.3±0.6keV (=3.9x107K) log EM2(cm-3) 55.8 Wind NH, hot component (1021cm-2) 2.7+2.3-2.0 T1 0.14+0.06-0.04keV (=1.2x106K) log EM1(cm-3) 57.4 Wind NH, 1 component (1021cm-2) 5.9+1.1-0.9 Flux 2±0.5x10-12 Unabsorbed flux 8±2x10-11 Luminosity (ergs/s) 2.5x1034 [d(kpc)/(1.67kpc)]2 Fe K Line central energy (keV) 6.65+0.1-0.2 Fe K equivalent width (keV) 1.7±0.3 Fe K flux (photons/s/cm2) 6(±0.4)x10-4 History: From electronic version of the journal
(End) James Marcout, Patricia Bauer [CDS] 29-Apr-2002
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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