ULLYSES News

ULLYSES Data Release 2

17 MAR 2021

The second ULLYSES Data Release (DR2) is now available! This data release includes medium- and high-resolution UV spectra and associated high-level science products (HLSPs) for 122 massive stars in the Large and Small Magellanic Clouds, 13 T Tauri stars in the Ori OB1 and Sigma Ori star-forming regions, and 5 non-ULLYSES targets that were present in STIS slit observations. Full details can be found on the Data Release 2 page. Of the 122 massive stars included in DR2, 115 were previously released in DR1. Updated HLSPs now incorporate calibration updates as well as improvements to the co-addition algorithm. 80 massive stars now include FUSE data. All STIS CCD data, and a subset of STIS NUV-MAMA data, for the 13 T Tauri stars have been custom calibrated by the ULLYSES team. 4 T Tauri stars had a total of 5 companions present in STIS slit observations. Special calibration steps taken for observations can include: custom hot pixel identification and flagging, defringing for G750L observations, and customized spectral extraction parameters for T Tauri stars and their companions.

Data products are available from this website (HLSPs and contributing data), the MAST Data Discovery Portal (HLSPs and contributing data), or directly as a High-Level Science Product collection using the DOI (HLSPs only).

Questions can be directed to the HST/ULLYSES helpdesk.

ULLYSES Data Release 1

05 NOV 2020

The first ULLYSES Data Release (DR1) is now available! This first data release includes HST medium- and high-resolution UV spectra and associated high-level science products (HLSPs) for 115 massive stars in the Large and Small Magellanic Clouds. ULLYSES HLSPs consist of co-added spectra of a common instrument and grating, and abutted spectra of different instruments and/or gratings. Of the 115 hot stars included in DR1, 43 were recently observed with COS and STIS as part of the ULLYSES program; 8 of these 43 also have archival COS and STIS data. The remaining 72 targets have full UV coverage from archival programs (see the ULLYSES target lists for the LMC and SMC). Data products are available from this website (HLSPs and contributing data), the MAST Data Discovery Portal (HLSPs and contributing data), or directly as a High-Level Science Product collection using the DOI (HLSPs only). The remainder of the LMC and SMC samples will be observed over Cycles 28 and 29. T Tauri stars in the Orion Ori OB1a, b and Sigma Ori regions will begin to be observed in November 2020, and will be included in a future data release in Spring 2021. For more information, refer to the Data Release 1 notes.

Data products are available from this website (HLSPs and contributing data), the MAST Data Discovery Portal (HLSPs and contributing data), or directly as a High-Level Science Product collection using the DOI (HLSPs only).

Questions can be directed to the HST/ULLYSES helpdesk.

When Can I Get the Data

10 JUN 2020

The ULLYSES Team will release co-added spectral data every quarter after the observations start. The first data release, which will include COS and STIS co-added data only, is expected to be in Fall 2020. However, one can still download the usual raw and pipeline-processed data when they are archived (i.e., before the official data releases).

In order to access the raw and pipeline-processed data, go to the MAST Portal and login on the top right of the page. After you login, click on "Subscriptions" in the top right of the page, which will open a Subscriptions tab in MAST. On the right side of the tab, there will be an icon that looks like a piece of mail and a green plus sign. When you hover over it with your mouse, it should say "Add a New Subscription". Click on this button and enter the information about what you'd like to subscribe to in the pop-up window. By subscribing to a ULLYSES program ID, you will be notified when the data taken for that program are archived. Again, those data will be the usual raw and standard pipeline-processed data — not the co-added High Level Science Products (HLSP) created by the ULLYSES team, which will be made available via the quarterly data releases.

For any questions, please contact the ULLYSES team at ullyses@stsci.edu.

ULLYSES future releases

01 JUN 2020

The ULLYSES Team is working to bring high quality data and analysis tools to the user community. In the near future, we will provide a database and quicklook tool to aid the community in exploring and analyzing ULLYSES data.

The database tool will allow a user to view and sort tables of information about the ULLYSES targets, query the ULLYSES Database on scientific metadata, select data points on an interactive plot, and download data for selected datasets.

The quicklook tool will allow quick visualization of a spectrum of interest, together with select file header information and metadata. It will also include options to plot the signal-to-noise ratio, data quality flags, errors, and a model spectrum over the observed spectrum. Finally, a user will have the option to download the high level science products associated with the target.

The ULLYSES team will also provide sample Jupyter notebooks, in order to assist the community in more complex analyses that are beyond the scope of the ULLYSES high level science products. Some of the planned functions involve the selection and visualization of target availability, inspection of spatially resolved objects, identification of spectral lines, and comparisons of spectra to models.