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J/AJ/113/1939            VLA Survey of Hercules cluster. I. (Dickey 1997)

A VLA survey of the Hercules cluster. I. The H I data Dickey J. M. <Astron. J. 113, 1939 (1997)> =1997AJ....113.1939D
ADC_Keywords: Clusters, galaxy ; H I data Abstract: This paper presents results from a survey of lambda 21-cm emission from galaxies in the Hercules cluster, A2151 and A2147. Four VLA primary beam areas were covered, a total area of 0.9 square degrees, including some 120 spiral galaxies brighter than 17.5m. The velocity resolution is 44km/s, the angular resolution 25". The detection threshold at field center is 2.6x10^8 h^{-2}M in H I mass or about 1.8x1020cm-2^ in column density. There are 61 galaxies detected in H I, of which about 25 had been previously detected at lambda 21-cm. About ten of the detections correspond to galaxies that are very faint in the optical, mE≥18 or M≥-17mag-5logh. Some of these low surface brightness galaxies have very extended H I disks, with r≥15kpc. The abundance of H I is a strong function of position in the cluster, with galaxies in the south and west showing hardly any gas, and galaxies in the north and east of A2151 frequently having massive, extended gas disks. The morphology of the remnants of gas in galaxies in the south and west suggests that the intracluster medium is responsible for their H I deficiency, but there are also several dramatic galaxy mergers in progress. (c) 1997 American Astronomical Society. Description: The channel maps for the Hercules cluster are stored in 63 Encapsulated Postscript files named fig36.eps, fig37.eps, ... fig98.eps. For all figures, the contour levels are as in figure 15 in the printed paper. Objects: ---------------------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------------------- 16 05.2 +17 45 ACO 2151 = Hercules cluster 16 02.3 +15 55 ACO 2147 ---------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 97 63 Galaxies detected in H I table3.dat 34 372 Channel map centers eps/* 0 63 Velocity channel maps
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 9 A9 --- File Name of the file in eps sub-directory 11- 16 A6 --- Alias Galaxy alias (1) 18- 32 A15 --- Name Other name 34- 35 I2 h RAh Right ascension (B1950) 37- 38 I2 min RAm Right ascension (B1950) 40- 44 F5.2 s RAs Right ascension (B1950) 46- 47 I2 deg DEd Declination (B1950) 49- 50 I2 arcmin DEm Declination (B1950) 52- 55 F4.1 arcsec DEs Declination (B1950) 57- 61 I5 km/s V0 Center velocity 63- 65 I3 km/s DV Width velocity 67- 69 F3.1 --- fpb Primary beam attenuation factor 71- 73 I3 pix Area Area used for H I mass determinations (2) 75- 79 F5.1 10+8solMass MHI H I mass obtained from spectra integrals 81- 85 F5.1 10+8solMass Mext Maximum total H I mass obtained by extending the area 87- 91 F5.1 10+8solMass Mpeak H I mass contained within the central beam area 93- 97 F5.1 10+8solMass Mint Mass determined form the integrated flux
Note (1): Fields 'ne' (northeast), 'ce' (center), and 'sw' (southeast) cover different areas of A2151, while field '47' covers the center of A2147. Note (2): 1 pix = 6"
Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 6 A6 --- Alias Galaxy alias 8- 12 I5 km/s cz Center velocity of the channel 15- 17 I3 arcsec oRA *Right ascension offset 20- 22 I3 arcsec oDE *Declination offset 25- 28 F4.1 10+8solMass Mpeak *Peak H I mass in the channel 31- 34 F4.1 10+8solMass Mint *Integrated H I mass in the channel
Note on oRA, oDE: Offsets of the fitted peak position from the H I centroid position as given in table2.dat. Note on Mpeak, Mint: The peak and integrated H I mass contained in the velocity channel similar to the last two columns of table2.dat.
Origin: AAS CD-ROM series, Volume 9, 1997 Lee Brotzman [ADS] 29-Aug-1997 History: table2.dat was prepared via OCR at CDS.
(End) Patricia Bauer [CDS] 04-Feb-1998
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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