J/ApJ/800/120 Profiles of z<0.5 galaxies with Pan-STARRS1 (Zheng+, 2015)
The structure and stellar content of the outer disks of galaxies: a new view
from the Pan-STARRS1 medium deep survey.
Zheng Z., Thilker D.A., Heckman T.M., Meurer G.R., Burgett W.S.,
Chambers K.C., Huber M.E., Kaiser N., Magnier E.A., Metcalfe N.,
Price P.A., Tonry J.L., Wainscoat R.J., Waters C.
<Astrophys. J., 800, 120 (2015)>
=2015ApJ...800..120Z 2015ApJ...800..120Z
ADC_Keywords: Galaxies, optical ; Photometry, ugriz ; Extinction ; Morphology
Keywords: galaxies: evolution; galaxies: formation; galaxies: photometry
Abstract:
We present the results of an analysis of Pan-STARRS1 Medium Deep
Survey multi-band (grizy) images of a sample of 698 low-redshift disk
galaxies that span broad ranges in stellar mass, star-formation rate,
and bulge/disk ratio. We use population synthesis spectral energy
distribution fitting techniques to explore the radial distribution of
the light, color, surface mass density, mass/light ratio, and age of
the stellar populations. We characterize the structure and stellar
content of the galaxy disks out to radii of about twice Petrosian
r90, beyond which the halo light becomes significant. We measure
normalized radial profiles for sub-samples of galaxies in three bins
each of stellar mass and concentration. We also fit radial profiles to
each galaxy. The majority of galaxies have down-bending radial surface
brightness profiles in the bluer bands with a break radius at roughly
r90. However, they typically show single unbroken exponentials in
the reddest bands and in the stellar surface mass density. We find
that the mass/light ratio and stellar age radial profiles have a
characteristic "U" shape. There is a good correlation between the
amplitude of the down-bend in the surface brightness profile and the
rate of the increase in the M/L ratio in the outer disk. As we move
from late- to early-type galaxies, the amplitude of the down-bend and
the radial gradient in M/L both decrease. Our results imply a
combination of stellar radial migration and suppression of recent star
formation can account for the stellar populations of the outer disk.
Description:
The imaging data is taken from the Medium Deep Survey (MDS) fields of
the Pan-STARRS1 (PS1) telescope and camera. There are 10 MDS fields,
each with a 7deg2 field of view, observed in five wide bands (g, r,
i, z, y).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 137 698 Disk galaxy list
table2.dat 154 11718 Radial profiles
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See also:
J/AJ/146/104 : Dwarf gal. surface brightness profiles. I. (Herrmann+, 2013)
J/ApJ/750/99 : The Pan-STARRS1 photometric system (Tonry+, 2012)
J/ApJS/197/22 : The Carnegie-Irvine Galaxy Survey (GGS). II. (Li+, 2011)
J/ApJ/701/1965 : SINGS galaxies radial dust properties (Munoz-Mateos+, 2009)
J/MNRAS/393/1531 : BUDDA structural properties of galaxies (Gadotti+, 2009)
J/ApJS/173/538 : XUV-Disk galaxies in the Local Universe (Thilker+, 2007)
http://www.sdss3.org/ : SDSS-III home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [1/782] Internal galaxy identifier
5- 8 A4 --- Field PS1 MDS field identifier
10- 16 F7.3 deg RAdeg Right Ascension in decimal degrees (J2000) (1)
18- 27 F10.7 deg DEdeg Declination in decimal degrees (J2000) (1)
29- 32 F4.2 --- z [0/0.5] SDSS-DR8 redshift (1)
34- 38 F5.2 kpc r90 [0.7/40] Petrosian radius r90
40- 44 F5.2 kpc r50 Petrosian half-light radius r50 (4)
46- 50 F5.2 kpc rb [0.6/31] Break radius
52- 55 F4.2 --- ell [0/1] Ellipticity
57- 61 F5.2 [Msun] M* [7.2/12.4] Log total stellar mass M* (4)
63- 67 F5.2 [Msun/kpc2] mus [6.6/10.3] Log average stellar mass surface
density log(µs) (4)
69- 74 F6.2 [yr-1] sSFR [-12/-8.8] Log specific star formation rate
76- 79 F4.1 mag mur10 Zero point of inner r band profile fitting
µ10 (2)
81- 84 F4.1 mag mur20 Zero point of outer r band profile fitting
µ20 (2)
86- 89 F4.2 --- kr1 Slope of inner r band profile fitting k1 (2)
91- 94 F4.2 --- kr2 Slope of outer r band profile fitting k2 (2)
96- 98 F3.1 [Msun/kpc2] mum10 Log zero point of inner stellar mass
profile fitting µm10 (2)
100-103 F4.1 [Msun/kpc2] mum20 Log zero point of outer stellar mass
profile fitting µm20 (2)
105-109 F5.2 --- km1 Slope of inner stellar mass profile
fitting (2)
111-115 F5.2 --- km2 Slope of outer stellar mass profile
fitting (2)
117-120 F4.1 [Msun/Lsun] gam10 Log zero point of inner r band M/L
profile fitting γ10 (3)
122-125 F4.1 [Msun/Lsun] gam20 Log zero point of outer r band M/L
profile fitting γ20 (3)
127-131 F5.2 --- kg1 Slope of inner r band M/L profile fitting
kγ1 (3)
133-137 F5.2 --- kg2 Slope of outer r band M/L profile fitting
kγ2 (3)
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Note (1): From SDSS DR8 catalog (Adelman-McCarthy+, 2011, II/306;
superseded by V/139).
Note (2): We develop an objective automatic break finding algorithm and use
the inner-outer disk slope ratio k1/k2 as the break strength
indicator, where k1 and k2 are defined as:
µ(r) = µ10+k1r (if r<rb) (Eq.6)
µ(r) = µ20+k2r (if r>rb) (Eq.7)
where r is the radius of the profile, µ is the SB profile in
ABmag/arcsec2, µ10 and µ20 are the central SBs interpolated
using the inner and outer disk SB profiles, respectively, and rb is
the break radius. See section 6.
Note (3): For simplicity, we approximate the M/L profile using a skewed
"V"-shaped (instead of the more complicated "U"-shaped) function
similar to Equations 6 and 7 (see Note 2) as:
log(γ(r)) = log(γ10+kγ1r (if r<rb) (Eq.9)
γ(r) = γ20+kγ2r (if r>rb) (Eq.10)
where γ is the stellar M/L radial profile in M☉/L☉,
γ10 and γ20 are the central M/L interpolated using the
inner and outer disk M/L profiles, respectively. See section 6.3.
Note (4): the average stellar mass surface density is defined by
µs = M*/(2πr502)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- ID [1/782] Internal galaxy identifier
5- 9 F5.2 arcsec r [0.3/58] Radius from center
11- 15 F5.2 mag gmag [18.1/36.3] The PS1 g band AB magnitude
17- 23 F7.2 mag e_gmag [-264/521] Error in gmag
25- 29 F5.2 mag rmag The PS1 r band AB magnitude
31- 37 F7.2 mag e_rmag [-153/141]Error in rmag
39- 43 F5.2 mag imag The PS1 i band AB magnitude
45- 51 F7.2 mag e_imag [-870/220] Error in imag
53- 57 F5.2 mag zmag The PS1 z band AB magnitude
59- 65 F7.2 mag e_zmag [-143/1694] Error in zmag
67- 71 F5.2 mag ymag [16.4/32.9] The PS1 y band AB magnitude
73- 79 F7.2 mag e_ymag [-189/872] Error in ymag
81- 85 F5.2 [Msun/kpc2] mus [3.1/10.2] Log average stellar mass
surface density
87- 90 F4.2 [Msun/kpc2] e_mus [0/0.7] Error in mus
92- 96 F5.2 [Msun/yr/kpc2] SigSFR [-7/-0.9] Log surface Star Formation
Rate density
98-101 F4.2 [Msun/yr/kpc2] e_SigSFR [0/1.1] Error in SigSFR
103-108 F6.2 [yr-1] sSFR [-13/-7.9] Log specific star formation
rate
110-114 F5.2 [yr-1] e_sSFR [-0.3/0.9] Error in sSFR
116-124 E9.2 [Msun/Lsun] M/L [-52/46] Log mass to light ratio
126-134 E9.2 [Msun/Lsun] e_M/L [0/56.2] EGrror in M/L
136-139 F4.2 [yr] Age [8/10] Log age
141-144 F4.2 [yr] e_Age [0/0.7] Error in Age
146-149 F4.2 mag Av [0.03/2.1] The V band extinction
151-154 F4.2 mag e_Av [0/0.9] Error in Av
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 02-Jul-2015