Exploring the Structures and Substructures of the Andromeda Satellite Dwarf Galaxies Cassiopeia III, Perseus I, and Lacerta I
We present results from wide-field imaging of the resolved stellar populations of the dwarf spheroidal galaxies Cassiopeia III (And XXXII) and Perseus I (And XXXIII), two satellites in the outer stellar halo of the Andromeda galaxy (M31). Our WIYN pODI photometry traces the red giant star population...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astronomical Journal |
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| Online Access: | https://doi.org/10.3847/1538-3881/acf859 |
| _version_ | 1827799963544846336 |
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| author | Katherine L. Rhode Nicholas J. Smith Denija Crnojevic David J. Sand Ryan A. Lambert Enrico Vesperini Madison V. Smith Steven Janowiecki John J. Salzer Ananthan Karunakaran Kristine Spekkens |
| author_facet | Katherine L. Rhode Nicholas J. Smith Denija Crnojevic David J. Sand Ryan A. Lambert Enrico Vesperini Madison V. Smith Steven Janowiecki John J. Salzer Ananthan Karunakaran Kristine Spekkens |
| author_sort | Katherine L. Rhode |
| collection | DOAJ |
| description | We present results from wide-field imaging of the resolved stellar populations of the dwarf spheroidal galaxies Cassiopeia III (And XXXII) and Perseus I (And XXXIII), two satellites in the outer stellar halo of the Andromeda galaxy (M31). Our WIYN pODI photometry traces the red giant star population in each galaxy to ∼2.5−3 half-light radii from the galaxy center. We use the tip of the red giant branch (TRGB) method to derive distances of ( m − M ) _0 = 24.62 ± 0.12 mag (839 ${}_{-45}^{+48}$ kpc, or ${156}_{-13}^{+16}$ kpc from M31) for Cas III and 24.47 ± 0.13 mag (738 ${}_{-45}^{+48}$ kpc, or 351 ${}_{-16}^{+17}$ kpc from M31) for Per I. These values are consistent within the errors with TRGB distances derived from a deeper Hubble Space Telescope study of the galaxies’ inner regions. For each galaxy, we derive structural parameters, total magnitude, and central surface brightness. We also place upper limits on the ratio of neutral hydrogen gas mass to optical luminosity, confirming the gas-poor nature of both galaxies. We combine our data set with corresponding data for the M31 satellite galaxy Lacerta I (And XXXI) from earlier work and search for substructure within the RGB star populations of Cas III, Per I, and Lac I. We find an overdense region on the west side of Lac I at a significance level of 2.5 σ –3 σ and a low-significance filament extending in the direction of M31. In Cas III, we identify two modestly significant overdensities near the center of the galaxy and another at two half-light radii. Per I shows no evidence for substructure in its RGB star population, which may reflect this galaxy’s isolated nature. |
| first_indexed | 2024-03-11T19:59:47Z |
| format | Article |
| id | doaj.art-b2da614cb621452c92eb9444378e90d9 |
| institution | Directory Open Access Journal |
| issn | 1538-3881 |
| language | English |
| last_indexed | 2024-03-11T19:59:47Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astronomical Journal |
| spelling | doaj.art-b2da614cb621452c92eb9444378e90d92023-10-04T10:37:30ZengIOP PublishingThe Astronomical Journal1538-38812023-01-01166518010.3847/1538-3881/acf859Exploring the Structures and Substructures of the Andromeda Satellite Dwarf Galaxies Cassiopeia III, Perseus I, and Lacerta IKatherine L. Rhode0https://orcid.org/0000-0001-8283-4591Nicholas J. Smith1https://orcid.org/0000-0002-3222-2949Denija Crnojevic2https://orcid.org/0000-0002-1763-4128David J. Sand3https://orcid.org/0000-0003-4102-380XRyan A. Lambert4https://orcid.org/0000-0003-1548-4602Enrico Vesperini5https://orcid.org/0000-0003-2742-6872Madison V. Smith6https://orcid.org/0000-0002-1813-4053Steven Janowiecki7https://orcid.org/0000-0001-9165-8905John J. Salzer8https://orcid.org/0000-0001-8483-603XAnanthan Karunakaran9https://orcid.org/0000-0001-8855-3635Kristine Spekkens10https://orcid.org/0000-0002-0956-7949Department of Astronomy, Indiana University , 727 East Third Street, Bloomington, IN 47405, USA ; krhode@indiana.eduDepartment of Astronomy, Indiana University , 727 East Third Street, Bloomington, IN 47405, USA ; krhode@indiana.eduUniversity of Tampa , 401 West Kennedy Boulevard, Tampa, FL 33606, USASteward Observatory, University of Arizona , 933 North Cherry Avenue, Room N204, Tucson, AZ 85721, USADepartment of Astronomy, Indiana University , 727 East Third Street, Bloomington, IN 47405, USA ; krhode@indiana.eduDepartment of Astronomy, Indiana University , 727 East Third Street, Bloomington, IN 47405, USA ; krhode@indiana.eduDepartment of Astronomy, Indiana University , 727 East Third Street, Bloomington, IN 47405, USA ; krhode@indiana.eduUniversity of Texas , Hobby–Eberly Telescope, McDonald Observatory, TX 79734, USADepartment of Astronomy, Indiana University , 727 East Third Street, Bloomington, IN 47405, USA ; krhode@indiana.eduInstituto de Astrofisica de Andalucia (CSIC) , Glorieta de la Astronomia, E-18008 Granada, SpainDepartment of Physics and Space Science, Royal Military College of Canada , P.O. Box 17000, Station Forces Kingston, ON K7K 7B4, Canada; Department of Physics, Engineering Physics and Astronomy, Queen's University , Kingston, ON K7L 3N6, CanadaWe present results from wide-field imaging of the resolved stellar populations of the dwarf spheroidal galaxies Cassiopeia III (And XXXII) and Perseus I (And XXXIII), two satellites in the outer stellar halo of the Andromeda galaxy (M31). Our WIYN pODI photometry traces the red giant star population in each galaxy to ∼2.5−3 half-light radii from the galaxy center. We use the tip of the red giant branch (TRGB) method to derive distances of ( m − M ) _0 = 24.62 ± 0.12 mag (839 ${}_{-45}^{+48}$ kpc, or ${156}_{-13}^{+16}$ kpc from M31) for Cas III and 24.47 ± 0.13 mag (738 ${}_{-45}^{+48}$ kpc, or 351 ${}_{-16}^{+17}$ kpc from M31) for Per I. These values are consistent within the errors with TRGB distances derived from a deeper Hubble Space Telescope study of the galaxies’ inner regions. For each galaxy, we derive structural parameters, total magnitude, and central surface brightness. We also place upper limits on the ratio of neutral hydrogen gas mass to optical luminosity, confirming the gas-poor nature of both galaxies. We combine our data set with corresponding data for the M31 satellite galaxy Lacerta I (And XXXI) from earlier work and search for substructure within the RGB star populations of Cas III, Per I, and Lac I. We find an overdense region on the west side of Lac I at a significance level of 2.5 σ –3 σ and a low-significance filament extending in the direction of M31. In Cas III, we identify two modestly significant overdensities near the center of the galaxy and another at two half-light radii. Per I shows no evidence for substructure in its RGB star population, which may reflect this galaxy’s isolated nature.https://doi.org/10.3847/1538-3881/acf859Dwarf galaxiesLocal GroupAndromeda GalaxyDwarf spheroidal galaxiesSloan photometryBroad band photometry |
| spellingShingle | Katherine L. Rhode Nicholas J. Smith Denija Crnojevic David J. Sand Ryan A. Lambert Enrico Vesperini Madison V. Smith Steven Janowiecki John J. Salzer Ananthan Karunakaran Kristine Spekkens Exploring the Structures and Substructures of the Andromeda Satellite Dwarf Galaxies Cassiopeia III, Perseus I, and Lacerta I The Astronomical Journal Dwarf galaxies Local Group Andromeda Galaxy Dwarf spheroidal galaxies Sloan photometry Broad band photometry |
| title | Exploring the Structures and Substructures of the Andromeda Satellite Dwarf Galaxies Cassiopeia III, Perseus I, and Lacerta I |
| title_full | Exploring the Structures and Substructures of the Andromeda Satellite Dwarf Galaxies Cassiopeia III, Perseus I, and Lacerta I |
| title_fullStr | Exploring the Structures and Substructures of the Andromeda Satellite Dwarf Galaxies Cassiopeia III, Perseus I, and Lacerta I |
| title_full_unstemmed | Exploring the Structures and Substructures of the Andromeda Satellite Dwarf Galaxies Cassiopeia III, Perseus I, and Lacerta I |
| title_short | Exploring the Structures and Substructures of the Andromeda Satellite Dwarf Galaxies Cassiopeia III, Perseus I, and Lacerta I |
| title_sort | exploring the structures and substructures of the andromeda satellite dwarf galaxies cassiopeia iii perseus i and lacerta i |
| topic | Dwarf galaxies Local Group Andromeda Galaxy Dwarf spheroidal galaxies Sloan photometry Broad band photometry |
| url | https://doi.org/10.3847/1538-3881/acf859 |
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