The codes below perform the calculations as described in Pol, Lam, McLaughlin, Lazio, and Cordes (2019). We have two components. The first estimates the redshift of an FRB given an observed DM. The second estimates the host DM of an FRB given the redshift.

These codes can be run in one of two ways: from the command line and from directly within python (compatible with versions 2/3). The code also needs the NE2001 code (found here) to be installed before the program can be executed.

FRB Redshift Estimator

Command Line

To calculate the redshift of an FRB,

usage: frbz.py [-h] [--NE2001 NEDIR] [--unweighted] [--ymw] [--hostdm HOSTDM]
               [--mwdm MWDM]
               dm dmerr ...

FRB Redshift Estimator

positional arguments:
  dm               Observed DM [pc cm^-3]
  dmerr            Error on observed DM [pc cm^-3]
  galcoord         If --mwdm is not provided, two values separated by a space:
                   Galactic latitude and Galactic longitude [deg]

optional arguments:
  -h, --help       show this help message and exit
  --NE2001 NEDIR   Path pointing to the NE2001 bin.NE2001/ directory location
  --unweighted     Use uniform weighted distribution (versus matter weighted
                   distribution
  --ymw            Use YMW model instead of NE2001
  --hostdm HOSTDM  Host DM [pc cm^-3]
  --mwdm MWDM      Milky Way DM [pc cm^-3]

Python function

calcz(dm,dmerr,mwarg,hostdm=0.0,weighted=True,evaluate=True,NEDIR="NE2001/bin.NE2001/", ymw = False)

Calculates the PDF for the redshift of the FRB
dm        : DM value [pc cm^-3]
dmerr     : DM error [pc cm^-3]
mwarg     : Either:
          : tuple of (Galactic longitude, Galactic latitude) in [deg], or
          : Milky Way DM [pc cm^-3]

weighted  : use matter weighted distribution if true
evaluate  : if true, returns the DM value with minus and plus errors
ymw	: Set flag to true to use YMW16 model instead of NE2001 model
-----
Returns
* A PDF instance of the redshift if evaluate = False
* The redshift value, the minus uncertainity, the plus uncertainty

FRB Host DM Estimator

Command Line

To calculate the host DM of an FRB,

usage: frbhostdm.py [-h] [--NE2001 NEDIR] [--unweighted] [--ymw] [--mwdm MWDM]
                    z dm dmerr ...

FRB Host DM Estimator

positional arguments:
  z               Redshift
  dm              Observed DM [pc cm^-3]
  dmerr           Error on observed DM [pc cm^-3]
  galcoord        If --mwdm is not provided, two values separated by a space:
                  Galactic latitude and Galactic longitude [deg]

optional arguments:
  -h, --help      show this help message and exit
  --NE2001 NEDIR  Path pointing to the NE2001 bin.NE2001/ directory location
  --unweighted    Use uniform weighted distribution (versus matter weighted
                  distribution
  --ymw           Use YMW model instead of NE2001
  --mwdm MWDM     Milky Way DM [pc cm^-3]

Python function

calchostDM(z,dm,dmerr,mwarg,weighted=True,evaluate=True,NEDIR="NE2001/bin.NE2001/", ymw = False)

Calculates the PDF for the host DM of the FRB
z         : Redshift
dm        : DM value [pc cm^-3]
dmerr     : DM error [pc cm^-3]
mwarg     : Either:
          : tuple of (Galactic longitude, Galactic latitude) in [deg], or
          : Milky Way DM [pc cm^-3]

weighted  : use matter weighted distribution if true
evaluate  : if true, returns the DM value with minus and plus errors
ymw	: Set flag to true to use YMW16 model instead of NE2001 model
-----
Returns
* A PDF instance of the redshift if evaluate = False
* The host DM value, the minus uncertainity, the plus uncertainty