Star formation at the edge of the Local Group: a rising star formation history in the isolated galaxy WLM
© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society We present the star formation history (SFH) of the isolated (D ∼ 970 kpc) Local Group dwarf galaxy Wolf-Lundmark-Melotte (WLM) measured from colour-magnitude diagrams (CMDs) constructed from deep Hu...
| Main Authors: | , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Oxford University Press (OUP)
2021
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| Online Access: | https://hdl.handle.net/1721.1/132571 |
| _version_ | 1826191524119969792 |
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| author | Albers, Saundra M Weisz, Daniel R Cole, Andrew A Dolphin, Andrew E Skillman, Evan D Williams, Benjamin F Boylan-Kolchin, Michael Bullock, James S Dalcanton, Julianne J Hopkins, Philip F Leaman, Ryan McConnachie, Alan W Vogelsberger, Mark Wetzel, Andrew |
| author_facet | Albers, Saundra M Weisz, Daniel R Cole, Andrew A Dolphin, Andrew E Skillman, Evan D Williams, Benjamin F Boylan-Kolchin, Michael Bullock, James S Dalcanton, Julianne J Hopkins, Philip F Leaman, Ryan McConnachie, Alan W Vogelsberger, Mark Wetzel, Andrew |
| author_sort | Albers, Saundra M |
| collection | MIT |
| description | © 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society We present the star formation history (SFH) of the isolated (D ∼ 970 kpc) Local Group dwarf galaxy Wolf-Lundmark-Melotte (WLM) measured from colour-magnitude diagrams (CMDs) constructed from deep Hubble Space Telescope imaging. Our observations include a central (0.5 rh) and outer field (0.7 rh) that reach below the oldest main-sequence turn-off. WLM has no early dominant episode of star formation: 20 per cent of its stellar mass formed by ∼12.5 Gyr ago (z ∼ 5). It also has an SFR that rises to the present with 50 per cent of the stellar mass within the most recent 5 Gyr (z < 0.7). There is evidence of a strong age gradient: the mean age of the outer field is 5 Gyr older than the inner field despite being only 0.4 kpc apart. Some models suggest such steep gradients are associated with strong stellar feedback and dark-matter core creation. The SFHs of real isolated dwarf galaxies and those from the Feedback in Realistic Environment suite are in good agreement for M*(z = 0) ∼ 107-109M☉, but in worse agreement at lower masses (M*(z = 0) ∼ 105-107 M☉). These differences may be explainable by systematics in the models (e.g. reionization model) and/or observations (HST field placement). We suggest that a coordinated effort to get deep CMDs between HST/JWST (crowded central fields) and WFIRST (wide-area halo coverage) is the optimal path for measuring global SFHs of isolated dwarf galaxies. |
| first_indexed | 2024-09-23T08:57:12Z |
| format | Article |
| id | mit-1721.1/132571 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T08:57:12Z |
| publishDate | 2021 |
| publisher | Oxford University Press (OUP) |
| record_format | dspace |
| spelling | mit-1721.1/1325712021-09-21T04:01:28Z Star formation at the edge of the Local Group: a rising star formation history in the isolated galaxy WLM Albers, Saundra M Weisz, Daniel R Cole, Andrew A Dolphin, Andrew E Skillman, Evan D Williams, Benjamin F Boylan-Kolchin, Michael Bullock, James S Dalcanton, Julianne J Hopkins, Philip F Leaman, Ryan McConnachie, Alan W Vogelsberger, Mark Wetzel, Andrew © 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society We present the star formation history (SFH) of the isolated (D ∼ 970 kpc) Local Group dwarf galaxy Wolf-Lundmark-Melotte (WLM) measured from colour-magnitude diagrams (CMDs) constructed from deep Hubble Space Telescope imaging. Our observations include a central (0.5 rh) and outer field (0.7 rh) that reach below the oldest main-sequence turn-off. WLM has no early dominant episode of star formation: 20 per cent of its stellar mass formed by ∼12.5 Gyr ago (z ∼ 5). It also has an SFR that rises to the present with 50 per cent of the stellar mass within the most recent 5 Gyr (z < 0.7). There is evidence of a strong age gradient: the mean age of the outer field is 5 Gyr older than the inner field despite being only 0.4 kpc apart. Some models suggest such steep gradients are associated with strong stellar feedback and dark-matter core creation. The SFHs of real isolated dwarf galaxies and those from the Feedback in Realistic Environment suite are in good agreement for M*(z = 0) ∼ 107-109M☉, but in worse agreement at lower masses (M*(z = 0) ∼ 105-107 M☉). These differences may be explainable by systematics in the models (e.g. reionization model) and/or observations (HST field placement). We suggest that a coordinated effort to get deep CMDs between HST/JWST (crowded central fields) and WFIRST (wide-area halo coverage) is the optimal path for measuring global SFHs of isolated dwarf galaxies. 2021-09-20T18:23:07Z 2021-09-20T18:23:07Z 2020-11-17T14:42:40Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/132571 en 10.1093/MNRAS/STZ2903 Monthly Notices of the Royal Astronomical Society Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Oxford University Press (OUP) arXiv |
| spellingShingle | Albers, Saundra M Weisz, Daniel R Cole, Andrew A Dolphin, Andrew E Skillman, Evan D Williams, Benjamin F Boylan-Kolchin, Michael Bullock, James S Dalcanton, Julianne J Hopkins, Philip F Leaman, Ryan McConnachie, Alan W Vogelsberger, Mark Wetzel, Andrew Star formation at the edge of the Local Group: a rising star formation history in the isolated galaxy WLM |
| title | Star formation at the edge of the Local Group: a rising star formation history in the isolated galaxy WLM |
| title_full | Star formation at the edge of the Local Group: a rising star formation history in the isolated galaxy WLM |
| title_fullStr | Star formation at the edge of the Local Group: a rising star formation history in the isolated galaxy WLM |
| title_full_unstemmed | Star formation at the edge of the Local Group: a rising star formation history in the isolated galaxy WLM |
| title_short | Star formation at the edge of the Local Group: a rising star formation history in the isolated galaxy WLM |
| title_sort | star formation at the edge of the local group a rising star formation history in the isolated galaxy wlm |
| url | https://hdl.handle.net/1721.1/132571 |
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