J/ApJ/812/34 Properties of UCD candidates in M87/M49/M60 regions (Liu+, 2015)
The Next Generation Virgo cluster Survey.
X. Properties of ultra-compact dwarfs in the M87, M49, and M60 regions.
Liu C., Peng E.W., Cote P., Ferrarese L., Jordan A., Mihos J.C.,
Zhang H.-X., Munoz R.P., Puzia T.H., Lancon A., Gwyn S., Cuillandre J.-C.,
Blakeslee J.P., Boselli A., Durrell P.R., Duc P.-A., Guhathakurta P.,
MacArthur L.A., Mei S., Sanchez-Janssen R., Xu H.
<Astrophys. J., 812, 34 (2015)>
=2015ApJ...812...34L 2015ApJ...812...34L (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Colors ; Extinction ; Photometry, ugriz ;
Radial velocities ; Galaxies, photometry
Keywords: galaxies: dwarf - galaxies: individual: M87, M49, M60 -
galaxies: nuclei - galaxies: star clusters: general
Abstract:
We use imaging from the Next Generation Virgo cluster Survey (NGVS) to
present a comparative study of ultra-compact dwarf (UCD) galaxies
associated with three prominent Virgo sub-clusters: those centered on
the massive red-sequence galaxies M87, M49, and M60. We show how UCDs
can be selected with high completeness using a combination of half-light
radius and location in color-color diagrams (u*iKs or u*gz).
Although the central galaxies in each of these sub-clusters have
nearly identical luminosities and stellar masses, we find large
differences in the sizes of their UCD populations, with M87 containing
∼3.5 and 7.8 times more UCDs than M49 and M60, respectively. The
relative abundance of UCDs in the three regions scales in proportion
to sub-cluster mass, as traced by X-ray gas mass, total gravitating
mass, number of globular clusters (GCs), and number of nearby
galaxies. We find that the UCDs are predominantly blue in color, with
∼85% of the UCDs having colors similar to blue GCs and stellar nuclei
of dwarf galaxies. We present evidence that UCDs surrounding M87 and
M49 may follow a morphological sequence ordered by the prominence of
their outer, low surface brightness envelope, ultimately merging with
the sequence of nucleated low-mass galaxies, and that envelope
prominence correlates with distance from either galaxy. Our analysis
provides evidence that tidal stripping of nucleated galaxies is an
important process in the formation of UCDs.
Description:
The NGVS is a deep optical imaging survey in the u*, g, i, and z bands,
with additional partial coverage in r, carried out with MegaCam, the
340 megapixel camera on CFHT (Boulade et al. 2003SPIE.4841...72B 2003SPIE.4841...72B). The
survey covers an area of Ω=104 deg2 inscribed within the
virial radii of the Virgo A (R200=1.55 Mpc) and Virgo B (R200=0.96 Mpc)
subclusters (Ferrarese et al. 2012ApJS..200....4F 2012ApJS..200....4F), which are centered
on M87 and M49, respectively. Beginning with the NGVS "pilot program"
(see Ferrarese et al. 2012ApJS..200....4F 2012ApJS..200....4F), images were collected
during six consecutive observing seasons, 2008 through 2013. Each
MegaCam pointing (i.e., NGVS field) measures roughly 1°x1° on the
sky. There is some overlap between fields, so that the 104 deg2 survey
area is covered by 117 distinct NGVS pointings.
Objects:
----------------------------------------------
RA (ICRS) DE Designation(s)
----------------------------------------------
12 30 49.42 +12 23 28.0 M87 = NGC 4486
12 29 46.80 +08 00 01.5 M49 = NGC 4472
12 43 40.01 +11 33 09.4 M60 = NGC 4649
----------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 139 127 Photometric Properties of UCD Candidates in
the M87 Region
table3.dat 135 127 Structural Properties and Redshift Information
for UCD Candidates in the M87 Region
table4.dat 139 50 Photometric Properties of UCD Candidates in
the M49 Region
table5.dat 135 50 Structural Properties and Redshift Information
for UCD Candidates in the M49 Region
table6.dat 139 29 Photometric Properties of UCD Candidates in
the M60 Region
table7.dat 135 29 Structural Properties and Redshift Information
for UCD Candidates in the M60 Region
--------------------------------------------------------------------------------
See also:
J/ApJ/613/279 : ACS Virgo Cluster Survey. III. M87 (Jordan+, 2004)
J/ApJS/197/33 : The M87 globular cluster system (Strader+, 2011)
J/ApJ/802/30 : NGVS VI. Ultra-compact dwarfs in M87 (Zhang+, 2015)
J/ApJ/819/162 : Chandra obs. of ultracompact dwarf galaxies (UCDs)
(Pandya+, 2016)
J/ApJS/227/12 : NGVS XXV. Virgo globular clusters photometry (Powalka+, 2016)
Byte-by-byte Description of file: table2.dat table4.dat table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID [1/127] Object identification number
5- 8 A4 --- --- [NGVS]
10- 28 A19 --- NGVS Object name in NGVS (NGVS JHHMMSS.ss+DDMMSS.s
in Simbad)
30- 40 F11.7 deg RAdeg Right Ascension in decimal degrees (J2000)
42- 51 F10.7 deg DEdeg Declination in decimal degrees (J2000)
53- 57 F5.3 mag E(B-V) Galactic extinction (Schlegel et al.
1998ApJ...500..525S 1998ApJ...500..525S)
59- 64 F6.3 mag gmag Aperture-corrected g-band magnitude within a
3-arcsec diameter aperture
66- 70 F5.3 mag e_gmag Uncertainty in gmag (1)
72- 76 F5.3 mag u*-g u*-g color index (2)
78- 82 F5.3 mag e_u*-g Uncertainty in u*-g (2)
84- 88 F5.3 mag g-r ? g-r color index (2)
90- 94 F5.3 mag e_g-r ? Uncertainty in g-r (2)
96-100 F5.3 mag g-i g-i color index (2)
102-106 F5.3 mag e_g-i Uncertainty in g-i (2)
108-112 F5.3 mag g-z g-z color index (2)
114-118 F5.3 mag e_g-z Uncertainty in g-z (2)
120-124 F5.3 mag g-Ks ? g-Ks color index (2)
126-130 F5.3 mag e_g-Ks ? Uncertainty in g-Ks (2)
132-137 F6.3 mag Deltaenv Envelope parameter defined in Equation (8) (3)
139 A1 --- UCD [0/1] Object flag (G1)
--------------------------------------------------------------------------------
Note (1): Only SExtractor errors are accounted for here.
Note (2): Colors measured in a 1.5-arcsec diameter aperture.
Note (3): Δenv=g16-g32. Where g16 and g32 are the g-band
corrected point-source magnitudes measured in apertures of diameter
16 and 32 pixels.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat table5.dat table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- ID [1/127] Object identification number
5- 8 A4 --- --- [NGVS]
10- 28 A19 --- NGVS Object name in NGVS (NGVS JHHMMSS.ss+DDMMSS.s
in Simbad)
30- 35 F6.3 mag gmag King model magnitude in g-band
37- 41 F5.3 mag e_gmag Uncertainty in gmag
43- 48 F6.3 mag imag King model magnitude in i-band
50- 54 F5.3 mag e_imag Uncertainty in imag
56- 60 F5.2 pc rh-g Half-light radius in g-band
62- 65 F4.2 pc e_rh-g Uncertainty in rh-g
67- 71 F5.2 pc rh-i Half-light radius in i-band
73- 76 F4.2 pc e_rh-i Uncertainty in rh-i
78- 82 F5.2 pc rhACS ? Half-light radius measured using HST imaging
(Hasegan et al. 2005ApJ...627..203H 2005ApJ...627..203H)
84- 87 F4.2 pc e_rhACS ? Uncertainty in rhACS
89- 92 F4.1 pc rhS11 ? Half-light radius from Strader et al.
(2011, J/ApJS/197/33)
94- 97 I4 km/s RVS11 ? Radial velocity from Strader et al.
(2011, J/ApJS/197/33)
99-104 I6 km/s RVMMT ? Radial velocity from MMT/Hectospec
106-110 I5 km/s RVAAT ? Radial velocity from 2dF/AAOmega AAT program
(Zhang et al. 2015, J/ApJ/802/30)
112-117 I6 km/s RVSDSS ? Radial velocity from SDSS (York et al.
2000AJ....120.1579Y 2000AJ....120.1579Y)
119 I1 --- Class [1/4] Class parameter (1)
121 I1 --- u*iKs ? [0/1] Whether the object was selected in the
u*iKs color-color diagram or not (0=no, 1=yes)
123 I1 --- u*gz [0/1] Whether the object was selected in the
u*gz color-color diagram or not (0=no, 1=yes)
125 A1 --- UCD [0/1] Object flag (G1)
127-134 A8 --- Other Other name, if available
135 A1 --- n_Other [a] Note on Other (2)
--------------------------------------------------------------------------------
Note (1): Class parameter as follows:
1 = Probable ultracompact dwarf galaxy (UCD);
2 = Dwarf nucleus;
3 = Background galaxy;
4 = Other type of contaminant.
Note (2): Note as follows:
a = The SDSS redshift measurement has ZWARNING=68, which means that the
spectrum has SMALLDELTACHI2 and NEGATIVE_EMISSION (Bolton et al.
2012AJ....144..144B 2012AJ....144..144B). Although the SDSS velocity indicates this
VCC-cataloged galaxy is a background galaxy, its diffuse envelope and
prominent nucleus strongly suggest that it is a bonafide cluster member.
--------------------------------------------------------------------------------
Global notes:
Note (G1): Flag as follows:
0 = Not ultracompact dwarf galaxy (UCD);
1 = Confirmed or possible UCD.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Ferrarese et al. Paper I 2012ApJS..200....4F 2012ApJS..200....4F
Paudel et al. Paper IV 2013ApJ...767..133P 2013ApJ...767..133P
Zhu et al. Paper V 2014ApJ...792...59Z 2014ApJ...792...59Z
Zhang et al. Paper VI 2015ApJ...802...30Z 2015ApJ...802...30Z Cat. J/ApJ/802/30
Sanchez-Janssen et al. Paper VII 2016ApJ...820...69S 2016ApJ...820...69S
Durrell et al. Paper VIII 2014ApJ...794..103D 2014ApJ...794..103D
Grossauer et al. Paper IX 2015ApJ...807...88G 2015ApJ...807...88G
Liu et al. Paper X 2015ApJ...812...34L 2015ApJ...812...34L This catalog
Raichoor et al. Paper XI 2014ApJ...797..102R 2014ApJ...797..102R
Guerou et al. Paper XII 2015ApJ...804...70G 2015ApJ...804...70G
Ferrarese et al. Paper XIII 2016ApJ...824...10F 2016ApJ...824...10F
Ferrarese et al. Paper XIV 2020ApJ...890..128F 2020ApJ...890..128F Cat. J/ApJ/890/128
Raichoor et al. Paper XV 2014ApJ...797..102R 2014ApJ...797..102R
Toloba et al. Paper XVI 2016ApJ...822...51T 2016ApJ...822...51T
Sun et al. Paper XVII 2019ApJ...885..145S 2019ApJ...885..145S
Cantiello et al. Paper XVIII 2018ApJ...856..126C 2018ApJ...856..126C
Lokhorst et al. Paper XIX 2016ApJ...819..124L 2016ApJ...819..124L
Licitra et al. Paper XX 2016ApJ...829...44L 2016ApJ...829...44L Cat. J/ApJ/829/44
Parroni et al. Paper XXI 2017ApJ...848..114P 2017ApJ...848..114P
Paudel et al. Paper XXII 2017ApJ...834...66P 2017ApJ...834...66P
Sanchez-Janssen et al. Paper XXIII 2019ApJ...878...18S 2019ApJ...878...18S Cat. J/ApJ/878/18
Roediger et al. Paper XXIV 2017ApJ...836..120R 2017ApJ...836..120R
Powalka et al. Paper XXV 2016ApJS..227...12P 2016ApJS..227...12P Cat. J/ApJS/227/12
Powalka et al. Paper XXVI 2017ApJ...844..104P 2017ApJ...844..104P
Fantin et al. Paper XXVIII 2017ApJ...843...53F 2017ApJ...843...53F
Lim et al. Paper XXX 2020ApJ...899...69L 2020ApJ...899...69L
Longobardi et al. Paper XXXI 2018ApJ...864...36L 2018ApJ...864...36L
Powalka et al. Paper XXXII 2018ApJ...856...84P 2018ApJ...856...84P
Liu et al. Paper XXXIV 2020ApJS..250...17L 2020ApJS..250...17L Cat. J/ApJS/250/17
(End) Prepared by Tiphaine Pouvreau [CDS] 04-Oct-2017