# MaStar Data Access

MaStar Data can be accessed using the SDSS Science Archive Server (SAS). There are two main files: one contains the summary tables and the other contains the spectra. You can download the files individually through a web browser, or automate the downloads via the "rsync" or "wget" commands.

Additionally, the Science Archive WebApp (SAW) provides a searchable interface for MaStar data, including an interactive view of spectra, and a data download facility: MaStar SAW.

## MaStar Output: Summary Table File

The "mastarall-[version].fits" file is a summary table containing information on the MaStar target, including the MaNGA ID, locations, photometry, input parameters, radial velocity, spectral quality flags, and more.

See the Data Model and the MaStar Catalogs page for more detail about the content of this file.

You can download this file through a web browser or using rsync:

rsync -avz rsync://data.sdss.org/dr15/manga/spectro/mastar/v2_4_3/v1_0_2/mastarall-v2_4_3-v1_0_2.fits

This catalog can also be queried using the CASJobs data access tool. Examples of MaStar queries can be found here.

## Spectra File

All high quality 1D MaStar spectra are located in the "mastar-goodspec-[version].fits" file:

​https://data.sdss.org/sas/dr15/manga/spectro/mastar/v2_4_3/v1_0_2/mastar-goodspec-v2_4_3-v1_0_2.fits.gz


Each entry in this file contains the spectrum and related information from one night (visit) of observation for a star. If a star has been observed on multiple nights (visits), then there will be multiple entries for that star. Spectra from multiple exposures on one night have been combined together to give a single visit spectrum of the target star for that night.

See the Data Model for the spectra file and the MaStar Spectra page for more detail.

You can download this file through a web browser using the SAS link above, or using rsync:

rsync -avz rsync://data.sdss.org/dr15/manga/spectro/mastar/v2_4_3/v1_0_2/mastar-goodspec-v2_4_3-v1_0_2.fits.gz

This catalog can also be queried using the CASJobs data access tool.

## Individual Spectra

Individual 1D spectra are also available on the SAS:

https://data.sdss.org/sas/dr15/manga/spectro/redux/v2_4_3/[PLATE]/mastar/mastar-LOG-[PLATE]-[IFUDESIGN].fits.gz

Where [PLATE] is the plate number and [IFUDESIGN] is the ID of the fiber bundle used to target this star.

See the Data Model for individual spectra file and the MaStar Spectra page for more detail.

Pay special attention to the spectral quality bitmasks, which provide essential information about the spectra which do not meet quality standards (e.g., bad flux calibration, high variance in radial velocity estimates, problematic visual inspection, etc.).

You can use the rsync command to automate the download of multiple spectra. For example, to download all spectra from a specific plate (e.g. 8037), use the command:

rsync -avz --include "*/" --include "mastar-LOG-*.fits.gz" --exclude "*" rsync://data.sdss.org/dr15/manga/spectro/redux/v2_4_3/8037/

Or, make a list of the paths you wish to download in a text file, e.g.

https://data.sdss.org/sas/dr15/manga/spectro/redux/v2_4_3/10008/mastar/mastar-LOG-10008-12701.fits.gz
https://data.sdss.org/sas/dr15/manga/spectro/redux/v2_4_3/10008/mastar/mastar-LOG-10008-12702.fits.gz
https://data.sdss.org/sas/dr15/manga/spectro/redux/v2_4_3/10008/mastar/mastar-LOG-10008-12703.fits.gz

and then forward that to “wget”:

wget -i [path to file list] ./

### Science Archive WebApp

The new Science Archive WebApp (SAW) provides a searchable interface for MaStar data, includes an interactive view of spectra, and a data download facility, available here.