J/ApJS/257/21 VERTICO: the Virgo EnviRonment Traced In CO survey (Brown+, 2021)
VERTICO: the Virgo EnviRonment Traced In CO survey.
Brown T., Wilson C.D., Zabel N., Davis T.A., Boselli A., Chung A.,
Ellison S.L., Lagos C.D.P., Stevens A.R.H., Cortese L., Bahe Y.M.,
Bisaria D., Bolatto A.D., Cashmore C.R., Catinella B., Chown R., Diemer B.,
Elahi P.J., Hani M.H., Jimenez-Donaire M.J., Lee B., Leidig K., Mok A.,
Olsen K.P., Parker L.C., Roberts I.D., Smith R., Spekkens K., Thorp M.,
Tonnesen S., Vienneau E., Villanueva V., Vogel S.N., Wadsley J., Welker C.,
Yoon H.
<Astrophys. J. Suppl. Ser., 257, 21 (2021)>
=2021ApJS..257...21B 2021ApJS..257...21B
ADC_Keywords: Galaxies; Carbon monoxide; Molecular data; Interstellar medium
Keywords: Galaxies ; Virgo Cluster ; Interstellar medium ; Molecular gas
Abstract:
We present the Virgo Environment Traced in CO (VERTICO) survey, a new
effort to map 12CO(2-1), 13CO(2-1), and C18O(2-1) in 51 Virgo
Cluster galaxies with the Atacama Compact Array, part of the Atacama
Large Millimeter/submillimeter Array. The primary motivation of
VERTICO is to understand the physical mechanisms that perturb
molecular gas disks, and therefore star formation and galaxy
evolution, in dense environments. This first paper contains an
overview of VERTICO's design and sample selection, 12CO(2-1)
observations, and data reduction procedures. We characterize global
12CO(2-1) fluxes and molecular gas masses for the 49 detected
VERTICO galaxies, provide upper limits for the two nondetections, and
produce resolved 12CO(2-1) data products (median
resolution=8"∼640pc). Azimuthally averaged 12CO(2-1) radial
intensity profiles are presented along with derived molecular gas
radii. We demonstrate the scientific power of VERTICO by comparing the
molecular gas size-mass scaling relation for our galaxies with a
control sample of field galaxies, highlighting the strong effect that
radius definition has on this correlation. We discuss the drivers of
the form and scatter in the size-mass relation and highlight areas for
future work. VERTICO is an ideal resource for studying the fate of
molecular gas in cluster galaxies and the physics of
environment-driven processes that perturb the star formation cycle.
Upon public release, the survey will provide a homogeneous legacy data
set for studying galaxy evolution in our closest cluster.
Description:
The Virgo EnviRonment Traced in CO (VERTICO) survey targets 51 Virgo
Cluster galaxies included in the Very Large Array Imaging of Virgo in
Atomic gas (VIVA) survey (Chung+ 2009AJ....138.1741C 2009AJ....138.1741C).
The Virgo region has been remarkably well surveyed at almost every
wavelength. See Section 2.
We observed 36 targets in CO(2-1), 13CO(2-1), C18O(2-1), and ALMA
Band 6 continuum in ALMA Cycle 7. The target galaxies are combined
with archival Atacama Compact Array (ACA) CO (2-1) data (7m and Total
Power arrays) for 14 massive Virgo Cluster spirals from the ALMA
component of the Physics at High Angular resolution in Nearby GalaxieS
project (PHANGS-ALMA; Leroy+ 2021ApJS..257...43L 2021ApJS..257...43L) and one from a
regular program (2016.1.00912.S; Cramer+ 2020ApJ...901...95C 2020ApJ...901...95C) to make
the final VERTICO sample of 51 galaxies.
Our final CO data cubes have a resolving beam of ∼7"-10", corresponding
to ∼0.6-0.8kpc at the distance of Virgo, and 10km/s velocity resolution.
Throughout this paper, we assume a common distance of 16.5Mpc to all
Virgo galaxies based on the Virgo Cluster distance found by
Mei+ (2007, J/ApJ/655/144).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 44 51 The VERTICO target sample
table2.dat 83 51 Global CO(2-1) line properties for the
51 VERTICO galaxies fits
table3.dat 27 49 Molecular gas disk radii estimates fits
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See also:
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
J/A+A/327/522 : Molecular gas content of spiral galaxies (Boselli+ 1997)
J/MNRAS/292/419 : Cooling flows in 207 clusters of galaxies (White+, 1997)
J/ApJ/655/144 : ACS Virgo Cluster Survey. XIII. (Mei+, 2007)
J/AJ/136/2782 : Star formation efficiency in nearby galaxies (Leroy+, 2008)
J/ApJ/703/1569 : Radial distribution in SINGS gal. I. (Munoz-Mateos+, 2009)
J/PASP/122/261 : Herschel Reference Survey Sample (Boselli+, 2010)
J/A+A/528/A107 : GALEX UV Virgo Cluster Survey (GUViCS) (Boselli+, 2011)
J/MNRAS/415/32 : COLD GASS survey (Saintonge+, 2011)
J/A+A/543/A161 : Submm obs. of 323 HRS nearby galaxies (Ciesla+, 2012)
J/A+A/544/A101 : GALEX obs. of Herschel Reference Survey (Cortese+, 2012)
J/A+A/564/A65 : Cold gas data of Herschel Reference Survey (Boselli+, 2014)
J/ApJS/215/22 : The Extended Virgo Cluster Catalog (EVCC) (Kim+, 2014)
J/MNRAS/460/2143 : HI size-mass relation of galaxies (Wang+, 2016)
J/ApJ/846/159 : Interferometric CO obs. of CALIFA galaxies (Bolatto+, 2017)
J/ApJS/233/22 : xCOLD GASS catalog (Saintonge+, 2017)
J/MNRAS/476/875 : xGASS catalog (Catinella+, 2018)
J/A+A/609/A37 : 875 nearby galaxies multiwavelength phot. (Clark+, 2018)
J/ApJ/860/172 : Cloud-scale molecular gas data in 15 galaxies (Sun+, 2018)
J/A+A/645/A111 : NGC 4654 CO(2-1) data cube (Lizee+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Name Galaxy name
9- 11 A3 --- f_Name Flag(s) on Name (1)
13- 19 F7.3 deg RAdeg [181/194] NED right ascension of the galaxy
optical center (J2000)
21- 27 F7.4 deg DEdeg [2/19.4] NED declination of the galaxy optical
center (J2000)
29- 33 I5 km/s Vel [-228/2538] NED optical heliocentric recession
velocity, νopt
35- 38 F4.1 deg Inc [13.6/90] Optical r-band inclination, i (2)
40- 44 F5.1 deg PA [1.8/356] Optical r-band position angle of the
kinematically redshifted half of the galaxy,
calculated east of north (2)
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Note (1): Flag as follows:
a = Data are from 7m and Total Power arrays. Other observations are 7m array
only.
b = Data are archival ALMA ACA (7m+total power) 12CO(2-1) observations at
comparable sensitivity to our Cycle 7 observations. The sources of
these data are the PHANGS-ALMA program (Leroy+ 2021ApJS..257...43L 2021ApJS..257...43L ;
14 galaxies) and one regular PI program (Cramer+ 2019ApJ...870...63C 2019ApJ...870...63C ;
NGC 4402).
See Section 3 and the Acknowledgments section for further details.
Note (2): Inclination and PA calculated using fits to SDSS photometry described
in Section 4.2.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- Name Galaxy name
9 A1 --- n_Name Flag on Name (3)
11- 15 F5.1 --- S/N [1.6/232.6]? Signal-to-noise ratio of
the integrated spectrum
17- 20 F4.1 arcsec Diamb [7.1/10.2] Diameter of the circularized
synthesized beam, θb
22- 24 I3 mJy rms [21/680] Integrated spectrum rms
in 10.6km/s channels
26- 29 I4 km/s Vlsr [-222/2501]? Local Standard of Rest
recession velocity of the line center (4)
31- 33 I3 km/s Delv [92/621]? Velocity width of the line
at zero intensity, Δνline
35 A1 --- l_Sco 3σ upper limit flag on Sco
37- 43 F7.2 Jy.km/s Sco [7.55/8369] Velocity-integrated CO flux
45- 46 I2 Jy.km/s e_Sco [6/45]? Sco uncertainty (5)
48 A1 --- l_logLCO 3σ upper limit flag on logLCO
50- 53 F4.2 [K.km/s.pc2] logLCO [6/9.2] CO line luminosity given
by Equation 5 (6)
55- 58 F4.2 [K.km/s.pc2] e_logLCO [0/0.27]? logLCO uncertainty
60 A1 --- l_TCO 3σ upper limit flag on TCO
62- 66 F5.2 K.km/s TCO [0.04/11.44] Mean velocity-integrated CO
intensity
68- 71 F4.2 K.km/s e_TCO [0.02/0.11]? TCO uncertainty
73 A1 --- l_logMmol 3σ upper limit flag on logMmol
75- 78 F4.2 [Msun] logMmol [6.84/9.88] logarithm of molecular gas mass
given by Equation 7 (7)
80- 83 F4.2 [Msun] e_logMmol [0/0.27]? logMmol uncertainty
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Note (3): Flag as follows:
a = Values are 3σ upper limits calculated over an on-sky circle
with radius=30" (projected radius ∼2.4kpc) and a line width of 100km/s.
The positions and systemic velocities used are listed in Table 1.
Note (4): Local standard of rest recession velocity of the line center,
calculated as the midpoint of Δνline
Note (5): We do not include the typical Band 6 calibration uncertainty of
5%-10% (0.02-0.04dex) in the flux measurement uncertainties. One may
add this in quadrature to account for this.
Note (6): Following Solomon & Vanden Bout (2005ARA&A..43..677S 2005ARA&A..43..677S), we calculate
the CO line luminosity, LCO, in K.km/s.pc2, expressed as the
product of the velocity-integrated source brightness temperature and
the source area, Equation (5):
LCO=3.25x107SCOνobs-2DL2,
where SCO is the velocity-integrated flux in Jy.km/s, νobs is
the observed frequency in GHz, and DL is the luminosity distance to
the source in Mpc. See Section 4.3.
Note (7): We convert CO luminosity to molecular gas mass, including the
contribution from heavy elements, in units of solar mass using the
relation, Equation (7):
Mmol=αCO/R21LCO,
where αCO=4.35M_☉/pc2(K.km/s)-1, the molecular gas
mass-to-CO (1-0) luminosity ratio calculated for the Milky Way disk
by Bolatto+ (2013ARA&A..51..207B 2013ARA&A..51..207B), and R21=0.8.
See Section 4.4.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name Galaxy name
9- 13 F5.3 kpc R50 [0.49/6.2] Radius containing 50% of the global
CO(2-1) flux
15- 20 F6.3 kpc R90 [1.3/11.2] Radius containing 90% of the global
CO(2-1) flux
22- 27 F6.3 kpc Riso [-0.08/9.8]? Inclination-corrected molecular
gas isodensity radius at
Σmol(r)=5M☉/pc2, at
the distance of Virgo 1"=80pc
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 17-Feb-2022