J/ApJ/966/93 Gas and star formation in Galaxy satellites (Jones+, 2024)
Gas and Star Formation in Satellites of Milky Way Analogs.
Jones M.G., Sand D.J., Karunakaran A., Spekkens K., Oman K.A., Bennet P.,
Besla G., Crnojevic D., Cuillandre J.-C., Fielder C.E., Gwyn S.,
Mutlu-Pakdil B.
<Astrophys. J., 966, 93 (2024)>
=2024ApJ...966...93J 2024ApJ...966...93J (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Stars, masses ; Ultraviolet ;
Photometry, H-alpha
Keywords: Dwarf galaxies - Galaxy quenching - Ram pressure stripped tails -
Interstellar atomic gas - Circumgalactic medium
Abstract:
We have imaged the entirety of eight (plus one partial) Milky Way
(MW)-like satellite systems, a total of 42 (45) satellites, from the
Satellites Around Galactic Analogs II catalog in both Hα and HI with
the Canada-France-Hawaii Telescope and the Jansky Very Large Array. In
these eight systems we have identified four cases where a satellite
appears to be currently undergoing ram pressure stripping (RPS) as its
HI gas collides with the circumgalactic medium (CGM) of its host. We
also see a clear suppression of gas fraction (MHI/M*) with decreasing
(projected) satellite-host separation-to our knowledge, the first time
this has been observed in a sample of MW-like systems. Comparisons to
the Auriga, A Project Of Simulating The Local Environment, and TNG50
cosmological zoom-in simulations show consistent global behavior, but
they systematically underpredict gas fractions across all satellites
by roughly 0.5 dex. Using a simplistic RPS model, we estimate the
average peak CGM density that satellites in these systems have
encountered to be logρcgm~-27.3g/cm3.
Furthermore, we see tentative evidence that these satellites are
following a specific star formation rate to gas fraction relation that
is distinct from field galaxies. Finally, we detect one new gas-rich
satellite in the UGC 903 system with an optical size and surface
brightness meeting the standard criteria to be considered an ultra-
diffuse galaxy.
Description:
HI mass and H-alpha star formation rate measurements of satellites in
nine Milky Way-like systems from the SAGA-II (Mao et al.,
2021ApJ...907...85M 2021ApJ...907...85M, Cat. J/ApJ/907/85) sample. Data were obtained
with the VLA and CFHT. NUV star formation rate estimates from
Karunakaran et al. (2021ApJ...916L..19K 2021ApJ...916L..19K, Cat. J/ApJ/916/L19) and
stellar mass estimated from Mao et al. (2021ApJ...907...85M 2021ApJ...907...85M, Cat.
J/ApJ/907/85) are also included.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 108 46 Satellite HI and Star Formation Properties
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See also:
J/ApJ/907/85 : SAGA Survey. II. Satellite systems around galaxies (Mao+, 2021)
J/ApJ/916/L19 : Satellites around MW analogs from SAGA II (Karunakaran+, 2021)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- Name Designation of satellite
21- 29 A9 --- Host Designation of host
31- 38 F8.4 deg RAdeg Right Ascension (J2000) of satellite
40- 47 F8.4 deg DEdeg Declination (J2000) of satellite
49- 51 I3 kpc Dproj Projected host-satellite separation
53- 56 I4 km/s Deltacz Velocity difference between
host and satellite
58- 62 F5.2 [Msun] logMstar Satellite stellar mass (Mao et al.,
2021ApJ...907...85M 2021ApJ...907...85M, Cat. J/ApJ/907/85)
64 A1 --- l_logSFRNUV [<] Lower limit flag on satellite NUV
star formation rate
66- 70 F5.2 [Msun/yr] logSFRNUV Satellite NUV star formation rate
(Karunakaran et al.,
2021ApJ...916L..19K 2021ApJ...916L..19K, Cat. J/ApJ/916/L19)
72- 75 F4.2 [Msun/yr] e_logSFRNUV ? Uncertainty of satellite NUV star
formation rate
77 A1 --- l_logSFRHa [<] Lower limit flag on satellite
H-alpha star formation rate
79- 83 F5.2 [Msun/yr] logSFRHa ? Satellite H-alpha star formation rate
85- 88 F4.2 [Msun/yr] e_logSFRHa ? Uncertainty of satellite H-alpha
star formation rate
90 A1 --- l_logMHI [<] Lower limit flag on satellite
HI mass
92- 95 F4.2 [Msun] logMHI ? Satellite HI mass
97-100 F4.2 [Msun] e_logMHI ? Uncertainty of satellite HI mass
102 A1 --- l_logMHI/Mstar [<] Lower limit flag on satellite
gas fraction
104-108 F5.2 [-] logMHI/Mstar ? Satellite gas fraction
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Acknowledgements:
Michael G. Jones, jonesmg(at)arizona.edu
(End) Patricia Vannier [CDS] 25-Sep-2024