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Astro::Misc(3)	      User Contributed Perl Documentation	Astro::Misc(3)

NAME
       Astro::Misc - Miscellaneous astronomical	routines

SYNOPSIS
	   use Astro::Misc;

	   $U =	calc_U($flux, $dist, $freq);
	   ($dist1, $dist2)= kindist($ra, $dec,	$vel, $epoch, $model);

DESCRIPTION
       Astro::Misc contains an assorted	set Perl routines for doing various
       astronomical calculations.

AUTHOR
       Chris Phillips  Chris.Phillips@csiro.au

FUNCTIONS
       read_possm
	    Read_possm interprets the output file from the AIPS	POSSM task.
	    the	task may be called repeatably if there is more than one	POSSM
	    output in the file.	The file must be open before calling
	    read_possm,	using the FileHandle module. The data from the possm
	    plot is returned in	a hash.	Some of	the header values are returned
	    as scalar values while the actual plot values are returned as
	    references to arrays. The scalar values returned are:
	      SOURCE, DATE, TIME, BANDWIDTH, TYPE (='A&P'||'R&I')
	    The	array references are: CHANNEL,
	      VELOCITY,	FREQUENCY, AMPLITUDE, PHASE, ANTENNA
	    The	global variable	$Astro::Misc:oldpossm (default=0) controls whether
	    old	or new style possm plots are read.  For	oldpossm=1, one	of
	    VELOCITY or	FREQUENCY will be a reference to an empty list (but the
	    hash value IS defined).

	    Usage:    use FileHandle
		      my $fh = FileHandle->new();
		      my %ahash	= ();
		      open($fh,	'possmfile');
		      read_possm($fh, %ahash);

	    Returns:  0	on success (but	not hit	eof)
		      1	on success (and	hit eof)
		      2	on premature eof

	    Examples of	hash usage:
		 $hash{SOURCE}	       # Source	name
		 @{$hash{VELOCITY}}    # Array of velocity values
		 ${$hash{PHASE}}[4]    # The fifth phase value

       read_lovas
	    Read_lovas read the	Lovas "Recommended Rest	Frequencies for	Observed
	    Interstellar Molecular Microwave Transitions - 1991	Revision"
	    (J.	Phys. Chem. Ref. Data, 21, 181-272, 1992). Alpha quality!!

	      my @lovas	= read_lovas($fname);
	      my @lovas	= read_lovas($fname, $minfreq, $maxfreq);

       calc_U
	     $U	= calc_U($flux,	$dist, $freq);

	    Calculate U	(Excitation Parameter) for an UCHII region
	    Based on Eqn 8 in Schraml and Mezger, 1969
	      $flux	   Integrated Source Flux Density (Jy)
	      $dist	   Distance to source (kpc)
	      $freq	   Frequency of	observation (GHz)
	    Note:
	     Uses the global variable $Astro::Misc::Temp for electron temperature
	     Default is	10000K

       calc_Nl
	     $Nl = calc_Nl($U);

	    Calculate the Lyman	continuum photon flux given U, the Excitation
	    Parameter for an UCHII region
	      $U is the	Excitation Parameter (from calc_U)
	     Ref: Kurtz	1994 ApJS 91 p659 Eq (1) (Original Origin unknown)

       lum2spectral
	     $spectral_type = lum2spectral($luminosity);

	    Calculate the spectral type	of a ZAMS star from its	luminosity
	    Based on Thompson 1984 ApJ 283 165 Table 1
	      $luminosity   Star luminosity (normalised	to Lsun)

       Nl2spectral
	     $spectral = Nl2spectral($Nl);

	    Calculate the spectral type	of a ZAMS star from its	flux of
	    Lyman Continuum Photons (Nl)
	    Based on Panagia, 1973, ApJ, 78, 929
	       $Nl     Flux of Lyman Continuum Photons

       kindist
	     ($dist1, $dist2)= kindist($ra, $dec, $vel,	$epoch,	$model);

	    Calculate the kinematic distance to	an object
	      $dist1, $dist2  Near/Far distance	(kpc)
	      $ra	      RA of object (turns)
	      $dec	      Dec of object (turns)
	      $vel	      LSR Velocity (km/s)
	      $epoch	      Epoch of coords (J2000/J/B1950/B)
	      $model	      Model to use (1 or 2)

	    Note:
	     Model 1 is	based on Brand and Blitz, 1993,	A&A, 275, 67-90.
	     Model 2 has unknown origin.

POD ERRORS
       Hey! The	above document had some	coding errors, which are explained
       below:

       Around line 65:
	   '=item' outside of any '=over'

	   =over without closing =back

perl v5.32.1			  2004-07-30			Astro::Misc(3)

NAME | SYNOPSIS | DESCRIPTION | AUTHOR | FUNCTIONS | POD ERRORS

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