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J/ApJ/602/850       JHK' photometry near IRAS 18507+0121     (Shepherd+, 2004)

Discovery of a massive protostar near IRAS 18507+0121. Shepherd D.S., Nurnberger D.E.A., Bronfman L. <Astrophys. J., 602, 850-859 (2004)> =2004ApJ...602..850S
ADC_Keywords: Radio sources ; H II regions ; Stars, pre-main sequence ; Photometry, infrared Keywords: H II regions - ISM: molecules - stars: formation - stars: pre-main-sequence Abstract: We have observed the massive star-forming region IRAS 18507+0121 at millimeter wavelengths in 3mm continuum emission, H13CO+ (J=1-0) and SiO (v=0,J=2-1) line emission, and at near-infrared (NIR) wavelengths between 1.2 and 2.1µm. Two compact molecular cores are detected: one north and one south, separated by ∼40". The northern molecular core contains a newly discovered, deeply embedded, B2 protostar surrounded by several hundred solar masses of warm gas and dust, G34.4+0.23 MM. Based on the presence of warm dust emission and the lack of detection at NIR wavelengths, we suggest that G34.4+0.23 MM may represent the relatively rare discovery of a massive protostar (e.g., analogous to a low-mass "Class 0" protostar). The southern molecular core is associated with an NIR cluster of young stars and an ultracompact HII region, G34.4+0.23, with a central B0.5 star. The fraction of NIR stars with excess infrared emission indicative of circumstellar material is greater than 50%, which suggests an upper limit on the age of the IRAS 18507+0121 star-forming region of 3Myr. Description: Simultaneous observations in the 3mm continuum band and H13CO+ (J=1-0) and SiO (v=0, J=2-1) lines were made with the Owens Valley Radio Observatory (OVRO) array of six 10.4m telescopes on 1998 April 19 and 1998 May 17. Broadband J, H, and K' (λc=1.25, 1.65, and 2.10µm, respectively) observations were performed in 1999 May at the Las Campanas 2.5m Du Pont Telescope using the facility NIR camera equipped with a NICMOS 3256x256 HgCdTe array detector. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 57 146 Positions and JHK' photometry of all detected sources
Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 3 I3 --- [SNB2004] Source number (1) 5- 9 F5.1 arcsec DelX The X position offset (2) 11- 15 F5.1 arcsec DelY The Y position offset (2) 17- 18 I2 h RAh Hour of Right Ascension (J2000) 20- 21 I2 min RAm Minute of Right Ascension (J2000) 23- 27 F5.2 s RAs Second of Right Ascension (J2000) 29 A1 --- DE- Sign of the Declination (J2000) 30- 31 I2 deg DEd Degree of Declination (J2000) 33- 34 I2 arcmin DEm Arcminute of Declination (J2000) 36- 39 F4.1 arcsec DEs Arcsecond of Declination (J2000) 41- 44 F4.1 mag Jmag ? The J band magnitude (3) 46- 49 F4.1 mag Hmag ? The H band magnitude (3) 51 A1 --- l_K'mag Limit flag on K 52- 55 F4.1 mag K'mag ? The K' band magnitude (3)
Note (1): Sources 54, 41, 43, 47, 49, 50, 53 and 55 are likely cluster members. Note (2): Relative to the position of the brightest member of the cluster (54). Note (3): Typical photometric errors are σ(J)∼1.2±0.5 magnitudes σ(H)∼1.4±0.6 magnitudes σ(K')∼1.6±0.6 magnitudes
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 07-May-2004
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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