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J/AJ/87/1165 Reddening Maps derived from HI and Galaxy Counts (Burstein+ 1982)
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Reddening Maps derived from HI and Galaxy Counts
Burstein A., Heiles C.
<Astron. J. 87, 1165 (1982)>
=1982AJ.....87.1165B
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ADC_Keywords: Reddening ; Extinction
Description:
Estimates of Galactic reddening E(B-V) are presented for most of the sky,
at a spatial resolution of 0.6 degree. The relative (point-to-point)
accuracy of the reddening is estimated to be 0.01 mag, or 10% of the
reddening, whichever is larger. No reddening data are provided for
Galactic latitudes within 10 degrees of the Galactic plane. There is
also a gap in coverage for southern Galactic latitudes less than -65 deg
which lie between Galactic longitudes 225 - 25 degrees.
The method used to predict the reddening values is dependent upon sky
location. For Galactic latitudes |b| between 10 and 65 degrees, and
declinations north of -23 degrees, the predictions are based on the
combination of Hat Creek/Parkes HI column densities and Shane-Wirtanen
galaxy counts, as explained in Burstein & Heiles (1978, AJ 225, 40).
Reddening predictions for directions south of -23 degrees declination,
and for |b| > 65 degrees use only the HI column densities (also explained
in the 1978 paper).
The reddening data are initially provided in ASCII (.asc) format (courtesy
of Michael Strauss), but are really meant to be used via binary file input.
To facilitate easy transference to binary file structure and use of these
files, two FORTRAN programs are provided (courtesy of Michael Strauss):
asc2bin.for - translates the ASCII files into binary, directly acccessible
files on your computer.
extinctn.for - A function which gives you the algorithms for calculating
reddenings from the binary files.
IMPORTANT! See the file redexpla.doc for details on usage of these programs.
By convention and usage, the reddenings of these maps are output by the
extinctn.for program as 4*E(B-V). Note, however, that it is E(B-V) that is
calculated by the Burstein and Heiles method. To get extinction in any
passband, one must multiply E(B-V) by the value appropriate for that
passband (see ApJ 225, 40, and AJ 87, 1162 for discussion on this point).
Detailed descriptions of these files are given in redexpla.doc.
Three GIF-format images of the derived E(B-V) values are also available.
Each of the three files shows a separate portion of the sky - when viewed
together, all available regions are presented.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
redexpla.doc 80 151 documentation for asc2bin.for, extinctn.for
extinctn.for 80 109 F77 func (input (l,b), get 4*E(B-V) )
asc2bin.for 80 72 F77 code (makes database for extinctn.for)
rednorth.asc 7 112800 input file to asc2bin.for
redsouth.asc 7 112800 input file to asc2bin.for
hinorth.asc 7 42210 input file to asc2bin.for
hisouth.asc 7 42210 input file to asc2bin.for
north.gif - - 900x400 GIF image of E(B-V), 65 < b < 10
south.gif - - 900x400 GIF image of E(B-V), -10 < b < -65
poles.gif - - 676x462 GIF image of E(B-V), |b| > 65
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References:
Burstein D., Heiles C.: 1978, ApJ 225, 40 =1978ApJ...225...40B
Burstein D., Heiles C.: 1978, ApLett 19, 69 =1978ApL....19...69B
Burstein D., Heiles C.: 1984, ApJS 54, 33 =1984ApJS...54...33B
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(End) David Burstein [ASU], J. Weiland [SSDOO/ADC] 17-Mar-1998