Predictions for the Detectability of Milky Way Satellite Galaxies and Outer-Halo Star Clusters with the Vera C. Rubin Observatory
We predict the sensitivity of the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) to faint, resolved Milky Way satellite galaxies and outer-halo star clusters. We characterize the expected sensitivity using simulated LSST data from the LSST Dark Energy Science Collaboration (DESC) D...
Saved in:
| Main Authors: | , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Maynooth Academic Publishing
2025-07-01
|
| Series: | The Open Journal of Astrophysics |
| Online Access: | https://doi.org/10.33232/001c.142072 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849427507516801024 |
|---|---|
| author | Kabelo Tsiane Sidney Mau Alex Drlica-Wagner Jeffrey L. Carlin Peter S. Ferguson Keith Bechtol Ethan O. Nadler Annika H. G. Peter Yao-Yuan Mao Adam J. Thornton LSST Dark Energy Science Collaboration |
| author_facet | Kabelo Tsiane Sidney Mau Alex Drlica-Wagner Jeffrey L. Carlin Peter S. Ferguson Keith Bechtol Ethan O. Nadler Annika H. G. Peter Yao-Yuan Mao Adam J. Thornton LSST Dark Energy Science Collaboration |
| author_sort | Kabelo Tsiane |
| collection | DOAJ |
| description | We predict the sensitivity of the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) to faint, resolved Milky Way satellite galaxies and outer-halo star clusters. We characterize the expected sensitivity using simulated LSST data from the LSST Dark Energy Science Collaboration (DESC) Data Challenge 2 (DC2) accessed and analyzed with the Rubin Science Platform as part of the Rubin Early Science Program. We simulate resolved stellar populations of Milky Way satellite galaxies and outer-halo star clusters over a wide range of sizes, luminosities, and heliocentric distances, which are broadly consistent with expectations for the Milky Way satellite system. We inject simulated stars into the DC2 catalog with realistic photometric uncertainties and star/galaxy separation derived from the DC2 data itself. We assess the probability that each simulated system would be detected by LSST using a conventional isochrone matched-filter technique. We find that assuming perfect star/galaxy separation enables the detection of resolved stellar systems with $M_V$ = 0 mag and $r_{1/2}$ = 10 pc with >50% efficiency out to a heliocentric distance of ~250 kpc. Similar detection efficiency is possible with a simple star/galaxy separation criterion based on measured quantities, although the false positive rate is higher due to leakage of background galaxies into the stellar sample. When assuming perfect star/galaxy classification and a model for the galaxy-halo connection fit to current data, we predict that 89 +/- 20 Milky Way satellite galaxies will be detectable with a simple matched-filter algorithm applied to the LSST wide-fast-deep data set. Different assumptions about the performance of star/galaxy classification efficiency can decrease this estimate by ~7-25%, which emphasizes the importance of high-quality star/galaxy separation for studies of the Milky Way satellite population with LSST. |
| format | Article |
| id | doaj-art-0206f48e6cdf421fa12c64cabac55f30 |
| institution | Kabale University |
| issn | 2565-6120 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | Maynooth Academic Publishing |
| record_format | Article |
| series | The Open Journal of Astrophysics |
| spelling | doaj-art-0206f48e6cdf421fa12c64cabac55f302025-08-20T03:29:02ZengMaynooth Academic PublishingThe Open Journal of Astrophysics2565-61202025-07-01810.33232/001c.142072Predictions for the Detectability of Milky Way Satellite Galaxies and Outer-Halo Star Clusters with the Vera C. Rubin ObservatoryKabelo TsianeSidney MauAlex Drlica-WagnerJeffrey L. CarlinPeter S. FergusonKeith BechtolEthan O. NadlerAnnika H. G. PeterYao-Yuan MaoAdam J. ThorntonLSST Dark Energy Science CollaborationWe predict the sensitivity of the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) to faint, resolved Milky Way satellite galaxies and outer-halo star clusters. We characterize the expected sensitivity using simulated LSST data from the LSST Dark Energy Science Collaboration (DESC) Data Challenge 2 (DC2) accessed and analyzed with the Rubin Science Platform as part of the Rubin Early Science Program. We simulate resolved stellar populations of Milky Way satellite galaxies and outer-halo star clusters over a wide range of sizes, luminosities, and heliocentric distances, which are broadly consistent with expectations for the Milky Way satellite system. We inject simulated stars into the DC2 catalog with realistic photometric uncertainties and star/galaxy separation derived from the DC2 data itself. We assess the probability that each simulated system would be detected by LSST using a conventional isochrone matched-filter technique. We find that assuming perfect star/galaxy separation enables the detection of resolved stellar systems with $M_V$ = 0 mag and $r_{1/2}$ = 10 pc with >50% efficiency out to a heliocentric distance of ~250 kpc. Similar detection efficiency is possible with a simple star/galaxy separation criterion based on measured quantities, although the false positive rate is higher due to leakage of background galaxies into the stellar sample. When assuming perfect star/galaxy classification and a model for the galaxy-halo connection fit to current data, we predict that 89 +/- 20 Milky Way satellite galaxies will be detectable with a simple matched-filter algorithm applied to the LSST wide-fast-deep data set. Different assumptions about the performance of star/galaxy classification efficiency can decrease this estimate by ~7-25%, which emphasizes the importance of high-quality star/galaxy separation for studies of the Milky Way satellite population with LSST.https://doi.org/10.33232/001c.142072 |
| spellingShingle | Kabelo Tsiane Sidney Mau Alex Drlica-Wagner Jeffrey L. Carlin Peter S. Ferguson Keith Bechtol Ethan O. Nadler Annika H. G. Peter Yao-Yuan Mao Adam J. Thornton LSST Dark Energy Science Collaboration Predictions for the Detectability of Milky Way Satellite Galaxies and Outer-Halo Star Clusters with the Vera C. Rubin Observatory The Open Journal of Astrophysics |
| title | Predictions for the Detectability of Milky Way Satellite Galaxies and Outer-Halo Star Clusters with the Vera C. Rubin Observatory |
| title_full | Predictions for the Detectability of Milky Way Satellite Galaxies and Outer-Halo Star Clusters with the Vera C. Rubin Observatory |
| title_fullStr | Predictions for the Detectability of Milky Way Satellite Galaxies and Outer-Halo Star Clusters with the Vera C. Rubin Observatory |
| title_full_unstemmed | Predictions for the Detectability of Milky Way Satellite Galaxies and Outer-Halo Star Clusters with the Vera C. Rubin Observatory |
| title_short | Predictions for the Detectability of Milky Way Satellite Galaxies and Outer-Halo Star Clusters with the Vera C. Rubin Observatory |
| title_sort | predictions for the detectability of milky way satellite galaxies and outer halo star clusters with the vera c rubin observatory |
| url | https://doi.org/10.33232/001c.142072 |
| work_keys_str_mv | AT kabelotsiane predictionsforthedetectabilityofmilkywaysatellitegalaxiesandouterhalostarclusterswiththeveracrubinobservatory AT sidneymau predictionsforthedetectabilityofmilkywaysatellitegalaxiesandouterhalostarclusterswiththeveracrubinobservatory AT alexdrlicawagner predictionsforthedetectabilityofmilkywaysatellitegalaxiesandouterhalostarclusterswiththeveracrubinobservatory AT jeffreylcarlin predictionsforthedetectabilityofmilkywaysatellitegalaxiesandouterhalostarclusterswiththeveracrubinobservatory AT petersferguson predictionsforthedetectabilityofmilkywaysatellitegalaxiesandouterhalostarclusterswiththeveracrubinobservatory AT keithbechtol predictionsforthedetectabilityofmilkywaysatellitegalaxiesandouterhalostarclusterswiththeveracrubinobservatory AT ethanonadler predictionsforthedetectabilityofmilkywaysatellitegalaxiesandouterhalostarclusterswiththeveracrubinobservatory AT annikahgpeter predictionsforthedetectabilityofmilkywaysatellitegalaxiesandouterhalostarclusterswiththeveracrubinobservatory AT yaoyuanmao predictionsforthedetectabilityofmilkywaysatellitegalaxiesandouterhalostarclusterswiththeveracrubinobservatory AT adamjthornton predictionsforthedetectabilityofmilkywaysatellitegalaxiesandouterhalostarclusterswiththeveracrubinobservatory AT lsstdarkenergysciencecollaboration predictionsforthedetectabilityofmilkywaysatellitegalaxiesandouterhalostarclusterswiththeveracrubinobservatory |