Catalog Modules

These modules contain the functions used to query external databases (including NED, PS1, and TNS) for data that astro_ghost needs to run.

NEDQueryFunctions

astro_ghost.NEDQueryFunctions.getNEDInfo(df)[source]

Gets galaxy information from NED, if it exists.

Parameters:

df (Pandas DataFrame) – Dataframe of the PS1 objects for which to query NED.

Returns:

The same dataframe as input, with NED info added.

Return type:

Pandas DataFrame

astro_ghost.NEDQueryFunctions.getNEDSpectra(df, path, verbose=False)[source]

Downloads NED spectra for the host galaxy, if it exists.

Parameters:

  • df (Pandas DataFrame) – Dataframe containing the associated transients and their host galaxies in PS1.

  • path (str) – Filepath where NED spectra should be saved.

  • verbose (boolean) – Whether to print relevant debugging information.

PS1QueryFunctions

astro_ghost.PS1QueryFunctions.checklegal(table, release)[source]
Checks if this combination of table and release is acceptable.

Raises a ValueError exception if there is problem.

Parameters:

  • table (str) – Table type. Can be 'mean', 'stack', or 'detection'

  • release (str) – The Pan-STARRS data release. Can be 'dr1' or 'dr2'.

Raises:

ValueError – Raises error if table and release combination are invalid.

astro_ghost.PS1QueryFunctions.create_dummy_df(nRows=1, fullDF=False)[source]

Creates a dummy PS1 dataframe (useful for running scripts when no sources found).

Parameters:

fullDF – If True, the dummy DataFrame replaces the full GHOST database.

Dtype fullDF:

Boolean

Returns:

Empty Pandas DataFrame with PS1 columns.

Return type:

Pandas DataFrame

astro_ghost.PS1QueryFunctions.find_all(name, path)[source]
Crawls through a directory and all its sub-directories looking for a file matching

'name'. If found, it is returned.

Parameters:

  • name (str) – The filename for which to search.

  • path (str) – The directory to search.

Returns:

The list of absolute paths to all files called 'name' in 'path'.

Return type:

list

astro_ghost.PS1QueryFunctions.find_host_info_PS1(df, fn, dict_fn, path, rad, append=0)[source]

Querying PS1 for all objects within rad arcsec of each SN.

Parameters:

  • df (Pandas DataFrame) – Dataframe of transient information (name and coordinates).

  • fn (str) – Filename of PS1 candidate host dataframe.

  • dict_fn (dictionary) – The filename of the dictionary to keep track of transient-candidate host matches. Keys are transient names, values are lists containing objIDs of all host candidates.

  • path (str) – The filepath where df will be saved.

  • rad (float) – The search radius, in arcsec.

  • append (bool, optional) – If True, append results to fn. If False, create a new file.

astro_ghost.PS1QueryFunctions.find_host_info_SH(df, fn, dict_fn, path, rad)[source]

VO Cone Search for all objects within rad arcsec of SNe (for Southern-Hemisphere (SH) objects).

Parameters:

  • df (Pandas DataFrame) – Dataframe of transient information (name and coordinates).

  • fn (str) – Filename of PS1 candidate host dataframe.

  • dict_fn (dictionary) – The filename of the dictionary to keep track of transient-candidate host matches. Keys are transient names, values are lists containing objIDs of all host candidates.

  • path (str) – The filepath where df will be saved.

  • rad (float) – The search radius, in arcsec.

  • append (bool, optional) – If True, append results to fn. If False, create a new file.

astro_ghost.PS1QueryFunctions.getAllPostageStamps(df, tempSize, path='.', verbose=False)[source]
Loops through a pandas dataframe and saves PS1 stacked color images of all

host galaxies.

Parameters:

  • df (Pandas DataFrame) – Dataframe of PS1 sources.

  • tempSize (int) – The downloaded image will be tempSize x tempSize pixels.

  • path (str) – Filepath where images should be saved.

  • verbose (bool) – If true, The progress of the image downloads is printed.

astro_ghost.PS1QueryFunctions.getDR2_halfLightSizes(ra_arr, dec_arr, rad)[source]

Retrieves half-light radius information from DR2 for panstarrs sources.

Parameters:

  • ra_arr (list) – List of right ascension values, in degrees.

  • dec_arr (list) – List of declination values, in degrees.

  • rad (float) – The search radius, in arcseconds.

Returns:

Dataframe containing dr2 half-light radiuses.

Return type:

Pandas DataFrame

astro_ghost.PS1QueryFunctions.getDR2_petrosianSizes(ra_arr, dec_arr, rad)[source]

Retrieves petrosian radius information from DR2 for panstarrs sources.

Parameters:

  • ra_arr (list) – List of right ascension values, in degrees.

  • dec_arr (list) – List of declination values, in degrees.

  • rad (float) – The search radius, in arcseconds.

Returns:

Dataframe containing dr2 petrosian radiuses.

Return type:

Pandas DataFrame

astro_ghost.PS1QueryFunctions.get_PS1_Pic(path, objID, ra, dec, size, band, safe=False)[source]

Downloads PS1 picture (in fits) centered at a given location.

Parameters:

  • path (str) – The filepath where the fits file will be saved.

  • objID (int) – The PS1 objID of the object of interest (to save as filename).

  • ra (float) – Right ascension of position, in degrees.

  • dec (float) – Declination of position, in degrees.

  • size (int) – The extracted image size in pixels (0.25 arcsec/pixel)

  • band (str) – The PS1 band.

  • safe (bool, optional) – If True, include the objID of the object of interest in the filename (useful when saving multiple files at comparable positions).

astro_ghost.PS1QueryFunctions.get_PS1_type(path, ra, dec, size, band, type)[source]

Download and save PS1 imaging data in a given band of a given type.

Parameters:

  • path (str) – filepath where the image will be saved.

  • ra (float) – Right ascension of position, in degrees.

  • dec (float) – Declination of position, in degrees.

  • size (int) – The extracted image size in pixels (0.25 arcsec/pixel)

  • band (str) – The PS1 band.

  • type (str) – The type of imaging data to obtain. Options are given below for the PS1 stack. 'stack.mask' - indicate which pixels in the stack are good and which are bad 'stack.wt' - stack variance images 'stack.num' - contain the number of warps with valid data which contributed to each pixel 'stack.exp' - contain the exposure time in seconds which contributed to each pixel 'stack.expw' - weighted exposure time maps See more information at https://outerspace.stsci.edu/display/PANSTARRS/PS1+Stack+images.

astro_ghost.PS1QueryFunctions.get_hosts(path, transient_fn, fn_Host, rad)[source]
Wrapper function for getting candidate host galaxies in PS1 for dec>-30 deg and

in Skymapper for dec<-30 deg.

Parameters:

  • path (str) – Filepath where csv of candidate hosts should be saved.

  • transient_fn (str) – Filename of csv containing the transients to associate (and their coordinates).

  • fn_Host (str) – Filename of csv containing candidate host galaxy properties.

  • rad (float) – Search radius of the algorithm, in arcseconds.

Returns:

Dataframe of all candidate host galaxies.

Return type:

Pandas DataFrame

astro_ghost.PS1QueryFunctions.getcolorim(ra, dec, size=240, output_size=None, filters='grizy', format='jpg')[source]

Get a PS1 color image at a sky position.

Parameters:

  • ra (float) – Right ascension of position, in degrees.

  • dec (float) – Declination of position, in degrees.

  • size (int) – The extracted image size in pixels (0.25 arcsec/pixel)

  • output_size (int) – output (display) image size in pixels (default = size). The output_size has no effect for fits format images.

  • filters (str) – The string with filters to include.

  • format (str) – The data format (options are 'jpg', 'png' or 'fits').

Returns:

The image.

Return type:

PIL Image

astro_ghost.PS1QueryFunctions.getimages(ra, dec, size=240, filters='grizy', type='stack')[source]

Query ps1filenames.py service to get a list of images.

Parameters:

  • ra (float) – Right ascension of position, in degrees.

  • dec (float) – Declination of position, in degrees.

  • size (int) – The image size in pixels (0.25 arcsec/pixel)

  • filters (str) – A string with the filters to include

Returns:

The results of the search for relevant images.

Return type:

Astropy Table

astro_ghost.PS1QueryFunctions.geturl(ra, dec, size=240, output_size=None, filters='grizy', format='jpg', color=False, type='stack')[source]

Get the URL for images in the table.

Parameters:

  • ra (float) – Right ascension of position, in degrees.

  • dec (float) – Declination of position, in degrees.

  • size (int) – The extracted image size in pixels (0.25 arcsec/pixel)

  • output_size (int) – output (display) image size in pixels (default = size). The output_size has no effect for fits format images.

  • filters (str) – The string with filters to include.

  • format (str) – The data format (options are "jpg", "png” or "fits").

  • color (bool, optional) – If True, creates a color image (only for jpg or png format). If False, return a list of URLs for single-filter grayscale images.

Returns:

The url for the image to download.

Return type:

str

astro_ghost.PS1QueryFunctions.mastQuery(request)[source]

Perform a MAST query.

Parameters:

request (dictionary) – The MAST request json object.

Returns:

The response HTTP headers.

Return type:

HTTP header

Returns:

The data obtained.

Return type:

str

astro_ghost.PS1QueryFunctions.ps1cone(ra, dec, radius, table='stack', release='dr1', format='csv', columns=None, baseurl='https://catalogs.mast.stsci.edu/api/v0.1/panstarrs', verbose=False, **kw)[source]

Do a cone search of the PS1 catalog. Note that this is just a thin wrapper for the function 'ps1search'.

Parameters:

  • ra (float) – Right ascension of central coordinate, in J200 degrees.

  • dec (float) – Declination of central coordinate, in J2000 degrees.

  • radius (float) – Search radius, in degrees (<= 0.5 degrees)

  • table (str) – Table type. Can be 'mean', 'stack', or 'detection'

  • release (str) – The Pan-STARRS data release. Can be 'dr1' or 'dr2'.

  • format (str) – Can be 'csv', 'votable', or 'json'.

  • columns (str) – Column names to include (None means use defaults).

  • baseurl (str) – Base URL for the request.

  • verbose (bool) – If true, print info about request.

  • **kw (dictionary) – Other parameters (e.g., 'nDetections.min':2). Note that this is required!

Returns:

Result of PS1 query, in 'csv', 'votable', or 'json' format.

Return type:

Same as ‘format’

astro_ghost.PS1QueryFunctions.ps1crossmatch_GLADE(foundGladeHosts)[source]

Gets PS1 photometry for GLADE sources by crossmatching.

Parameters:

foundGladeHosts (Pandas DataFrame) – DataFrame of Glade sources to cross-match in ps1

astro_ghost.PS1QueryFunctions.ps1metadata(table='mean', release='dr1', baseurl='https://catalogs.mast.stsci.edu/api/v0.1/panstarrs')[source]
Return metadata for the specified catalog and table. Snagged from the

wonderful API at https://ps1images.stsci.edu/ps1_dr2_api.html.

Parameters:

  • table (str) – Table type. Can be 'mean', 'stack', or 'detection'

  • release (str) – The Pan-STARRS data release. Can be 'dr1' or 'dr2'.

  • baseurl (str) – Base URL for the request.

Returns:

Table with columns name, type, description.

Return type:

Astropy Table

astro_ghost.PS1QueryFunctions.ps1search(table='mean', release='dr1', format='csv', columns=None, baseurl='https://catalogs.mast.stsci.edu/api/v0.1/panstarrs', verbose=False, **kw)[source]

Do a general search of the PS1 catalog (possibly without ra/dec/radius).

Parameters:

  • table (str) – Table type. Can be 'mean', 'stack', or 'detection'

  • release (str) – The Pan-STARRS data release. Can be 'dr1' or ‘dr2'.

  • format (str) – Can be 'csv', 'votable', or 'json'.

  • columns (str) – Column names to include (None means use defaults).

  • baseurl (str) – Base URL for the request.

  • verbose (bool) – If true, print info about request.

  • **kw (dictionary) – Other parameters (e.g., 'nDetections.min':2). Note that this is required!

Returns:

Result of PS1 query, in 'csv', 'votable', or 'json' format.

Return type:

Same as ‘format’

astro_ghost.PS1QueryFunctions.resolve(name)[source]

Get the RA and Dec for an object using the MAST name resolver.

Parameters:

name (str) – Name of the object of interest.

Returns:

Position of resolved object, in degrees.

Return type:

tuple

astro_ghost.PS1QueryFunctions.southernSearch(ra, dec, rad)[source]

Conducts a cone search for Skymapper objects at a given position.

Parameters:

  • ra (float) – Right ascension of central coordinate, in J200 degrees.

  • dec (float) – Declination of central coordinate, in J2000 degrees.

  • radius (float) – Search radius, in degrees (<= 0.5 degrees)

Returns:

Dataframe of Skymapper objects formatted to be joined with PS1 sources.

Return type:

Pandas DataFrame.

SimbadQueryFunctions

astro_ghost.SimbadQueryFunctions.getSimbadInfo(df)[source]

Check if a given PS1 object is in Simbad.

Parameters:

df (Pandas DataFrame) – PS1 properties for candidate hosts.

Returns:

PS1 properties for hosts, with added column ‘hasSimbad’.

Return type:

Pandas DataFrame

TNSQueryFunctions

astro_ghost.TNSQueryFunctions.getTNSSpectra(transients, path, verbose=False)[source]

Scrapes the Transient Name Server for all public spectra of a transient.

Parameters:

  • transients (Pandas DataFrame) – Dataframe of transient information (must contain the column ‘Name’).

  • path (str) – Filepath where spectra will be saved.

  • verbose (bool, optional) – If True, print progress.