Abstract
We present our discovery and analysis of dwarf galaxies in the NGC 3585 galaxy group by the Korea Microlensing Telescope Network (KMTNet) Supernova Program. Using deep stack images reaching ≃28 mag arcsec-2 in BVI, we discovered 46 dwarf galaxy candidates distributed in a field of 7 square degrees. The dwarf galaxy candidates exhibit a central surface brightness as faint as μ 0,V = 26.2 mag arcsec-2, with effective radii larger than 150 pc and total absolute magnitudes brighter than M V ≈ -10 mag, if at the distance of NGC 3585. The dwarf galaxy surface number density decreases with projected distance from NGC 3585. We estimate the background contamination to be about 20% based both on the number density profile and on diffuse galaxy counts in a control field. The dwarf galaxy colors and Sérsic structural parameters are consistent with those found for other dwarf galaxies. Unusually, there is no indication of a change in color or brightness in the dwarf galaxy candidates with projected distance from the group center. Approximately 20% of the candidates contain an unresolved nucleus. The nucleated fraction is larger for brighter (and redder) galaxies, but is independent of distance from the group center. We identify four ultra-diffuse galaxy candidates, all near the group center. We interpret these spatial properties as suggesting that the NGC 3585 group might be dynamically younger than the typical group. The galaxy luminosity function of the NGC 3585 group has a faint-end slope of α ≈ -1.39, which is roughly consistent with the slopes found for other nearby groups. The possible dependence of the slope on global group properties is still unclear and continues to motivate our homogeneous deep survey of dozens of nearby groups.
| Original language | English (US) |
|---|---|
| Article number | 88 |
| Journal | Astrophysical Journal |
| Volume | 885 |
| Issue number | 1 |
| DOIs | |
| State | Published - Nov 1 2019 |
Keywords
- galaxies: dwarf
- galaxies: groups: individual (NGC 3585)
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science
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In: Astrophysical Journal, Vol. 885, No. 1, 88, 01.11.2019.
Research output: Contribution to journal › Article › peer-review
}
TY - JOUR
T1 - Dwarf Galaxy Discoveries from the KMTNet Supernova Program. II. The NGC 3585 Group and Its Dynamical State
AU - Park, Hong Soo
AU - Moon, Dae Sik
AU - Zaritsky, Dennis
AU - Kim, Sang Chul
AU - Lee, Youngdae
AU - Cha, Sang Mok
AU - Lee, Yongseok
N1 - Funding Information: Hong Soo Park Dae-Sik Moon Dennis Zaritsky Sang Chul Kim Youngdae Lee Sang-Mok Cha Yongseok Lee Hong Soo Park Dae-Sik Moon Dennis Zaritsky Sang Chul Kim Youngdae Lee Sang-Mok Cha Yongseok Lee Korea Astronomy and Space Science Institute, 776, Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of Korea Dept. of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4, Canada Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85719, USA Korea University of Science and Technology (UST), Daejeon 34113, Republic of Korea Department of Astronomy and Space Science, Chungnam National University, 99 Daehak-ro, Daejeon 34134, Republic of Korea School of Space Research, Kyung Hee University, Yongin, Kyeonggi 17104, Republic of Korea Hong Soo Park, Dae-Sik Moon, Dennis Zaritsky, Sang Chul Kim, Youngdae Lee, Sang-Mok Cha and Yongseok Lee 2019-11-01 2019-11-01 10:42:04 cgi/release: Article released bin/incoming: New from .zip yes We present our discovery and analysis of dwarf galaxies in the NGC 3585 galaxy group by the Korea Microlensing Telescope Network (KMTNet) Supernova Program. Using deep stack images reaching ≃28 mag arcsec −2 in BVI , we discovered 46 dwarf galaxy candidates distributed in a field of 7 square degrees. The dwarf galaxy candidates exhibit a central surface brightness as faint as μ 0, V �=�26.2 mag arcsec −2 , with effective radii larger than 150 pc and total absolute magnitudes brighter than M V �≈�−10 mag, if at the distance of NGC 3585. The dwarf galaxy surface number density decreases with projected distance from NGC 3585. We estimate the background contamination to be about 20% based both on the number density profile and on diffuse galaxy counts in a control field. The dwarf galaxy colors and S�rsic structural parameters are consistent with those found for other dwarf galaxies. Unusually, there is no indication of a change in color or brightness in the dwarf galaxy candidates with projected distance from the group center. Approximately 20% of the candidates contain an unresolved nucleus. The nucleated fraction is larger for brighter (and redder) galaxies, but is independent of distance from the group center. We identify four ultra-diffuse galaxy candidates, all near the group center. We interpret these spatial properties as suggesting that the NGC 3585 group might be dynamically younger than the typical group. The galaxy luminosity function of the NGC 3585 group has a faint-end slope of α �≈�−1.39, which is roughly consistent with the slopes found for other nearby groups. The possible dependence of the slope on global group properties is still unclear and continues to motivate our homogeneous deep survey of dozens of nearby groups. � 2019. The American Astronomical Society. All rights reserved. Abraham R. G. and van Dokkum P. G. 2014 PASP 126 55 10.1086/674875 Abraham R. G. and van Dokkum P. G. PASP 1538-3873 126 935 55 2014 55 Afsariardchi N., Moon D.-S., Drout M. R. et al 2019 ApJ 881 22 10.3847/1538-4357/ab2be6 Afsariardchi N., Moon D.-S., Drout M. 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PY - 2019/11/1
Y1 - 2019/11/1
N2 - We present our discovery and analysis of dwarf galaxies in the NGC 3585 galaxy group by the Korea Microlensing Telescope Network (KMTNet) Supernova Program. Using deep stack images reaching ≃28 mag arcsec-2 in BVI, we discovered 46 dwarf galaxy candidates distributed in a field of 7 square degrees. The dwarf galaxy candidates exhibit a central surface brightness as faint as μ 0,V = 26.2 mag arcsec-2, with effective radii larger than 150 pc and total absolute magnitudes brighter than M V ≈ -10 mag, if at the distance of NGC 3585. The dwarf galaxy surface number density decreases with projected distance from NGC 3585. We estimate the background contamination to be about 20% based both on the number density profile and on diffuse galaxy counts in a control field. The dwarf galaxy colors and Sérsic structural parameters are consistent with those found for other dwarf galaxies. Unusually, there is no indication of a change in color or brightness in the dwarf galaxy candidates with projected distance from the group center. Approximately 20% of the candidates contain an unresolved nucleus. The nucleated fraction is larger for brighter (and redder) galaxies, but is independent of distance from the group center. We identify four ultra-diffuse galaxy candidates, all near the group center. We interpret these spatial properties as suggesting that the NGC 3585 group might be dynamically younger than the typical group. The galaxy luminosity function of the NGC 3585 group has a faint-end slope of α ≈ -1.39, which is roughly consistent with the slopes found for other nearby groups. The possible dependence of the slope on global group properties is still unclear and continues to motivate our homogeneous deep survey of dozens of nearby groups.
AB - We present our discovery and analysis of dwarf galaxies in the NGC 3585 galaxy group by the Korea Microlensing Telescope Network (KMTNet) Supernova Program. Using deep stack images reaching ≃28 mag arcsec-2 in BVI, we discovered 46 dwarf galaxy candidates distributed in a field of 7 square degrees. The dwarf galaxy candidates exhibit a central surface brightness as faint as μ 0,V = 26.2 mag arcsec-2, with effective radii larger than 150 pc and total absolute magnitudes brighter than M V ≈ -10 mag, if at the distance of NGC 3585. The dwarf galaxy surface number density decreases with projected distance from NGC 3585. We estimate the background contamination to be about 20% based both on the number density profile and on diffuse galaxy counts in a control field. The dwarf galaxy colors and Sérsic structural parameters are consistent with those found for other dwarf galaxies. Unusually, there is no indication of a change in color or brightness in the dwarf galaxy candidates with projected distance from the group center. Approximately 20% of the candidates contain an unresolved nucleus. The nucleated fraction is larger for brighter (and redder) galaxies, but is independent of distance from the group center. We identify four ultra-diffuse galaxy candidates, all near the group center. We interpret these spatial properties as suggesting that the NGC 3585 group might be dynamically younger than the typical group. The galaxy luminosity function of the NGC 3585 group has a faint-end slope of α ≈ -1.39, which is roughly consistent with the slopes found for other nearby groups. The possible dependence of the slope on global group properties is still unclear and continues to motivate our homogeneous deep survey of dozens of nearby groups.
KW - galaxies: dwarf
KW - galaxies: groups: individual (NGC 3585)
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U2 - 10.3847/1538-4357/ab4794
DO - 10.3847/1538-4357/ab4794
M3 - Article
AN - SCOPUS:85075245935
SN - 0004-637X
VL - 885
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 88
ER -