J/A+A/682/A110 Disc galaxies since z=1 sizes (Buitrago+, 2024)
Strong size evolution of disc galaxies since z=1.
Readdressing galaxy growth using a physically motivated size indicator.
Buitrago F., Trujillo I.
<Astron. Astrophys. 682, A110 (2024)>
=2024A&A...682A.110B 2024A&A...682A.110B (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Morphology ; Redshifts
Keywords: methods: observational - galaxies: evolution -
galaxies: fundamental parameters - galaxies: spiral -
galaxies: star formation - galaxies: structure
Abstract:
Our understanding of how the size of galaxies has evolved over cosmic
time is based on the use of the half-light (effective) radius as a
size indicator. Although the half-light radius has many advantages for
structurally parameterising galaxies, it does not provide a measure of
the global extent of the objects, but only an indication of the size
of the region containing the innermost 50% of the galaxy's light.
Therefore, the observed mild evolution of the effective radius of disc
galaxies with cosmic time is conditioned by the evolution of the
central part of the galaxies rather than by the evolutionary
properties of the whole structure. Expanding on recent works by
Trujillo et al. (2020MNRAS.493...87T 2020MNRAS.493...87T, Cat. J/MNRAS/493/87) and Chamba
et al. (2022A&A...667A..87C 2022A&A...667A..87C), we studied the size evolution of disc
galaxies using the radial location of the gas density threshold for
star formation as a size indicator. As a proxy to evaluate this
quantity, we used the radial position of the truncation (edge) in the
stellar surface mass density profiles of galaxies. To conduct this
task, we selected 1048 disc galaxies with M*>1010M☉ and
spectroscopic redshifts up to z=1 within the HST CANDELS fields. We
derived their surface brightness, colour and stellar mass density
profiles. Using the new size indicator, the observed scatter of the
size-mass relation (∼0.1dex) decreases by a factor of ∼2 compared to
that using the effective radius. At a fixed stellar mass, Milky
Way-like (MW-like; M*∼5x1010M☉) disc galaxies have, on
average, increased their sizes by a factor of two in the last 8Gyr,
while the surface stellar mass density at the edge position
(Sigmaedge) has decreased by more than an order of magnitude from
∼13M☉/pc^2* (z=1) to ∼1M☉/pc2 (z=0). These results
reflect a dramatic evolution of the outer part of MW-like disc
galaxies, with an average radial growth rate of its discs of about
1.5kpc/Gyr.
Description:
The main parameters of our sample 'coordinates, redshift,
masses, sizes (Redge) and the stellar surface mass densities at the
edge positions (Sigmaedge)' could be found in Table 1.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 95 1048 Galaxy sample main parameters
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See also:
J/MNRAS/493/87 : 1005 galaxies with z<0.09 sample (Trujillo+, 2020)
J/A+A/667/A87 : Edges of galaxies. Limits of star formation (Chamba+, 2022)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Galaxy CANDELS galaxy ID
7- 12 A6 --- Field CANDELS field
(COSMOS, EGS, GOODSN, GOODSS or UDS)
14- 25 F12.8 deg RAdeg Right ascension (J2000)
27- 38 F12.8 deg DEdeg Declination (J2000)
40- 47 F8.6 --- z Spectroscopic redshift
49- 57 F9.6 10+10Msun M* Stellar mass
59- 67 F9.7 10+10Msun e_M* Error in the stellar mass
69- 72 F4.1 kpc Redge Truncation edge
74 I1 kpc e_Redge [1] Error in the truncation edge
76- 84 F9.6 Msun/pc2 Sigmaedge Surface stellar mass density at
the edge position
86- 95 F10.7 Msun/pc2 e_Sigmaedge Error in the Sigmaedge
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Acknowledgements:
Fernando Buitrago, fbuitrago.astro(at)gmail.com
(End) Patricia Vannier [CDS] 12-Dec-2023