The Enigmatic (Almost) Dark Galaxy Coma P: Distance Measurement and Stellar Populations from HST Imaging

Samantha W. Brunker, Kristen B. W. Mcquinn, John J. Salzer, John M. Cannon, Steven Janowiecki, Lukas Leisman, Katherine L. Rhode, Elizabeth A. K. Adams, Catherine Ball, Andrew E. Dolphin, Riccardo Giovanelli, Martha P. Haynes

Research output: Contribution to journalArticle

Abstract

We present Hubble Space Telescope (HST) observations of the low surface brightness (SB) galaxy Coma P. This system was first discovered in the Arecibo Legacy Fast ALFA H I survey and was cataloged as an (almost) dark galaxy because it did not exhibit any obvious optical counterpart in the available survey data (e.g., Sloan Digital Sky Survey). Subsequent WIYN pODI imaging revealed an ultra-low SB stellar component located at the center of the H I detection. We use the HST images to produce a deep color-magnitude diagram of the resolved stellar population present in Coma P. We clearly detect a red stellar sequence that we interpret to be a red giant branch and use it to infer a tip of the red giant branch distance of 5.50(-0.53)(+0.28) Mpc. The new distance is substantially lower than earlier estimates and shows that Coma P is an extreme dwarf galaxy. Our derived stellar mass is only 4.3 x 10(5) M-circle dot, meaning that Coma P has an extreme H I-to-stellar mass ratio of 81. We present a detailed analysis of the galaxy environment within which Coma P resides. We hypothesize that Coma P formed within a local void and has spent most of its lifetime in a low-density environment. Over time, the gravitational attraction of the galaxies located in the void wall has moved it to the edge, where it had a recent "fly-by" interaction with M64. We investigate the possibility that Coma P is at a farther distance and conclude that the available data are best fit by a distance of 5.5 Mpc.

Original languageEnglish
Article number76
Number of pages15
JournalAstronomical Journal
Volume157
Issue number2
DOIs
Publication statusPublished - Feb 2019

Cite this

Brunker, S. W., Mcquinn, K. B. W., Salzer, J. J., Cannon, J. M., Janowiecki, S., Leisman, L., ... Haynes, M. P. (2019). The Enigmatic (Almost) Dark Galaxy Coma P: Distance Measurement and Stellar Populations from HST Imaging. Astronomical Journal, 157(2), [76]. https://doi.org/10.3847/1538-3881/aafb39
Brunker, Samantha W. ; Mcquinn, Kristen B. W. ; Salzer, John J. ; Cannon, John M. ; Janowiecki, Steven ; Leisman, Lukas ; Rhode, Katherine L. ; Adams, Elizabeth A. K. ; Ball, Catherine ; Dolphin, Andrew E. ; Giovanelli, Riccardo ; Haynes, Martha P. / The Enigmatic (Almost) Dark Galaxy Coma P : Distance Measurement and Stellar Populations from HST Imaging. In: Astronomical Journal. 2019 ; Vol. 157, No. 2.
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abstract = "We present Hubble Space Telescope (HST) observations of the low surface brightness (SB) galaxy Coma P. This system was first discovered in the Arecibo Legacy Fast ALFA H I survey and was cataloged as an (almost) dark galaxy because it did not exhibit any obvious optical counterpart in the available survey data (e.g., Sloan Digital Sky Survey). Subsequent WIYN pODI imaging revealed an ultra-low SB stellar component located at the center of the H I detection. We use the HST images to produce a deep color-magnitude diagram of the resolved stellar population present in Coma P. We clearly detect a red stellar sequence that we interpret to be a red giant branch and use it to infer a tip of the red giant branch distance of 5.50(-0.53)(+0.28) Mpc. The new distance is substantially lower than earlier estimates and shows that Coma P is an extreme dwarf galaxy. Our derived stellar mass is only 4.3 x 10(5) M-circle dot, meaning that Coma P has an extreme H I-to-stellar mass ratio of 81. We present a detailed analysis of the galaxy environment within which Coma P resides. We hypothesize that Coma P formed within a local void and has spent most of its lifetime in a low-density environment. Over time, the gravitational attraction of the galaxies located in the void wall has moved it to the edge, where it had a recent {"}fly-by{"} interaction with M64. We investigate the possibility that Coma P is at a farther distance and conclude that the available data are best fit by a distance of 5.5 Mpc.",
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author = "Brunker, {Samantha W.} and Mcquinn, {Kristen B. W.} and Salzer, {John J.} and Cannon, {John M.} and Steven Janowiecki and Lukas Leisman and Rhode, {Katherine L.} and Adams, {Elizabeth A. K.} and Catherine Ball and Dolphin, {Andrew E.} and Riccardo Giovanelli and Haynes, {Martha P.}",
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Brunker, SW, Mcquinn, KBW, Salzer, JJ, Cannon, JM, Janowiecki, S, Leisman, L, Rhode, KL, Adams, EAK, Ball, C, Dolphin, AE, Giovanelli, R & Haynes, MP 2019, 'The Enigmatic (Almost) Dark Galaxy Coma P: Distance Measurement and Stellar Populations from HST Imaging' Astronomical Journal, vol. 157, no. 2, 76. https://doi.org/10.3847/1538-3881/aafb39

The Enigmatic (Almost) Dark Galaxy Coma P : Distance Measurement and Stellar Populations from HST Imaging. / Brunker, Samantha W.; Mcquinn, Kristen B. W.; Salzer, John J.; Cannon, John M.; Janowiecki, Steven; Leisman, Lukas; Rhode, Katherine L.; Adams, Elizabeth A. K.; Ball, Catherine; Dolphin, Andrew E.; Giovanelli, Riccardo; Haynes, Martha P.

In: Astronomical Journal, Vol. 157, No. 2, 76, 02.2019.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The Enigmatic (Almost) Dark Galaxy Coma P

T2 - Distance Measurement and Stellar Populations from HST Imaging

AU - Brunker, Samantha W.

AU - Mcquinn, Kristen B. W.

AU - Salzer, John J.

AU - Cannon, John M.

AU - Janowiecki, Steven

AU - Leisman, Lukas

AU - Rhode, Katherine L.

AU - Adams, Elizabeth A. K.

AU - Ball, Catherine

AU - Dolphin, Andrew E.

AU - Giovanelli, Riccardo

AU - Haynes, Martha P.

PY - 2019/2

Y1 - 2019/2

N2 - We present Hubble Space Telescope (HST) observations of the low surface brightness (SB) galaxy Coma P. This system was first discovered in the Arecibo Legacy Fast ALFA H I survey and was cataloged as an (almost) dark galaxy because it did not exhibit any obvious optical counterpart in the available survey data (e.g., Sloan Digital Sky Survey). Subsequent WIYN pODI imaging revealed an ultra-low SB stellar component located at the center of the H I detection. We use the HST images to produce a deep color-magnitude diagram of the resolved stellar population present in Coma P. We clearly detect a red stellar sequence that we interpret to be a red giant branch and use it to infer a tip of the red giant branch distance of 5.50(-0.53)(+0.28) Mpc. The new distance is substantially lower than earlier estimates and shows that Coma P is an extreme dwarf galaxy. Our derived stellar mass is only 4.3 x 10(5) M-circle dot, meaning that Coma P has an extreme H I-to-stellar mass ratio of 81. We present a detailed analysis of the galaxy environment within which Coma P resides. We hypothesize that Coma P formed within a local void and has spent most of its lifetime in a low-density environment. Over time, the gravitational attraction of the galaxies located in the void wall has moved it to the edge, where it had a recent "fly-by" interaction with M64. We investigate the possibility that Coma P is at a farther distance and conclude that the available data are best fit by a distance of 5.5 Mpc.

AB - We present Hubble Space Telescope (HST) observations of the low surface brightness (SB) galaxy Coma P. This system was first discovered in the Arecibo Legacy Fast ALFA H I survey and was cataloged as an (almost) dark galaxy because it did not exhibit any obvious optical counterpart in the available survey data (e.g., Sloan Digital Sky Survey). Subsequent WIYN pODI imaging revealed an ultra-low SB stellar component located at the center of the H I detection. We use the HST images to produce a deep color-magnitude diagram of the resolved stellar population present in Coma P. We clearly detect a red stellar sequence that we interpret to be a red giant branch and use it to infer a tip of the red giant branch distance of 5.50(-0.53)(+0.28) Mpc. The new distance is substantially lower than earlier estimates and shows that Coma P is an extreme dwarf galaxy. Our derived stellar mass is only 4.3 x 10(5) M-circle dot, meaning that Coma P has an extreme H I-to-stellar mass ratio of 81. We present a detailed analysis of the galaxy environment within which Coma P resides. We hypothesize that Coma P formed within a local void and has spent most of its lifetime in a low-density environment. Over time, the gravitational attraction of the galaxies located in the void wall has moved it to the edge, where it had a recent "fly-by" interaction with M64. We investigate the possibility that Coma P is at a farther distance and conclude that the available data are best fit by a distance of 5.5 Mpc.

KW - galaxies: distances and redshifts

KW - galaxies: dwarf

KW - galaxies: evolution

KW - galaxies: individual (Coma P, AGC 229385)

KW - galaxies: irregular

KW - RED GIANT BRANCH

KW - STAR-FORMATION HISTORIES

KW - NEARBY GALAXIES

KW - ADVANCED CAMERA

KW - DWARF GALAXIES

KW - GASEOUS DISKS

KW - TIP

KW - EVOLUTION

KW - CALIBRATION

KW - ABUNDANCES

U2 - 10.3847/1538-3881/aafb39

DO - 10.3847/1538-3881/aafb39

M3 - Article

VL - 157

JO - The Astronomical Journal

JF - The Astronomical Journal

SN - 0004-6256

IS - 2

M1 - 76

ER -