Data

On BRIGHT, we provide all available photometry, spectroscopy, and the Prospector stellar population modeling fits and outputs when available. We also showcase a thumbnail of the host if we have imaging of it. Please see Fong et al. 2022 for details of photometric and spectroscopic reductions. The data presented here are largely derived from large ground-based telescopes, including the twin Magellan telescopes (Baade/Clay), Keck I and Keck II, Gemini-North and South, the Large Binocular Telescope, and the MMT. We also include data from the Hubble Space Telescope and supplement with data from the literature and archival surveys.

On the individual pages for each GRB, we provide references for where all the data is from. If the reference is "BRIGHT", please refer to the Acknowledgments page to determine if you should cite Fong et al. 2022 or Nugent et al. 2022. We note that while we try to provide as many filters points as possible for each short GRB host in the catalog, the data here are not all-inclusive of what exists in the literature.

Thumbnails

Almost all the hosts in our catalogue have a thumbnail image, and the host is highlighted with the orange crosshairs. If there is no image, we do not have any available data to make a thumbnail. A thumbnail outlined in pink highlights the "hostless" short GRBs, we show the XRT position, and optical afterglow position of the short GRB when available (e.g. GRB 160410A). A thumbnail outlined in blue is an “observing constraint” field, and we cannot draw any conclusions on the host galaxy (e.g. GRB 180402A).

Photometry

We provide photometry and upper limits of the host galaxies in the JSON files and on the individual host pages. All tabulated photometry is in apparent AB magnitudes and is not corrected for Galactic extinction in the direction of the burst. Uncertainties on the reported photometry correspond to 1-sigma. We note that if a photometric value is "-1", it does not exist (although a FITS file might), and if the error is "0" in the JSON file, that denotes an upper limit.

While we provide at least one astrometrically-corrected data set for every burst, not all filters will have proper astrometry or even have native WCS. We aim to provide proper native WCS to all images in the future. Images may also come in either counts or counts per second.

We note that the photometry which appears in the Prospector SED plots are corrected for Galactic extinction.

Spectroscopy

We provide 3-column CSV files of the extracted 1D spectrum for available hosts. Wavelength is in Angstroms and the spectrum and error are in micro-Jy. After flux calibration, we have normalized the spectra to the respective photometry of their hosts. In some cases, the spectra do not have enough signal to identify their redshifts, but we make them available anyway.

Downloadable Data

You'll notice that there are a few data files available for download for each SGRB host. We describe what each of these files are as well as how you can use the information each of these below. We note that if you click something to download and it takes you to the main media page instead of downloading the file, that means the file does not exist.

Nested Sampling Samples (h5 file): This h5 file contains the nested sampling "chains" from the Prospector fit of the host. Please see the Prospector documentation to learn how to read these files and our Prospector tutorial on the Population Modeling page. The nested sampling chains are most useful for creating posterior distributions of each sampled stellar population property (e.g., the corner plot).

Metadata (JSON file): This JSON dictionary contains all the information listed in the tables on the individual pages for a SGRB host. You will not find arrays of the observed spectrum or model photometry and spectra from the Prospector fits here. This file is best used to extract properties of the host (with 1-sigma errors) and SGRB itself, with relevant sources. Telescopes for the observed data are also listed. Please see this tutorial for understanding how to read the JSON files and the data within them!

FITS: The FITS files are images of the SGRB host and the surrounding galaxies in the available photometric bands. You can use these images to better understand the host and its surrounding environment. While we have aimed to provide proper astrometry for at least one FITS image per GRB, not all FITS images have astrometric corrections. We plan to provide this in the future.

CSV Files: There are either two or three CSV files available for download. Every SGRB host has two CSV files containing the model photometry and spectrum from the Prospector fit, both of which are normalized to the observed photometry and are in units of micro-Jy. Several hosts also have an observed spectrum, which is a third CSV file and contains the spectrum, error spectrum (both in micro-Jy), and wavelengths (in Angstroms). You can use these files to create model SED's, similar to the ones shown on the individual pages.