J/MNRAS/437/1070 DYNAMO. Hα luminous galaxies sample (Green+, 2014)
DYNAMO. I. A sample of Hα-luminous galaxies with resolved kinematics.
Green A.W., Glazebrook K., McGregor P.J., Damjanov I., Wisnioski E.,
Abraham R.G., Colless M., Sharp R.G., Crain R.A., Poole G.B., McCarthy P.J.
<Mon. Not. R. Astron. Soc., 437, 1070-1095 (2014)>
=2014MNRAS.437.1070G 2014MNRAS.437.1070G
ADC_Keywords: Galaxy catalogs ; Photometry, H-alpha ; Morphology
Keywords: galaxies: evolution - galaxies: formation -
galaxies: kinematics and dynamics - galaxies: star formation
Abstract:
DYNAMO is a multiwavelength, spatially resolved survey of local
(z∼0.1) star-forming galaxies designed to study evolution through
comparison with samples at z≃2. Half of the sample has
integrated H{alpha luminosities of >1042erg/s, the typical lower
limit for resolved spectroscopy at z≃2. The sample covers a
range in stellar mass (109-1011M{sun) and star formation rate
(0.2-100M☉/yr). In this first paper of a series, we present
integral-field spectroscopy of H{alpha emission for the sample of 67
galaxies. We infer gas fractions in our sample as high as ≃0.8,
higher than typical for local galaxies. Gas fraction correlates with
stellar mass in galaxies with star formation rates below
10M☉/yr, as found by COLDGASS, but galaxies with higher star
formation rates have higher than expected gas fractions. There is only
a weak correlation, if any, between gas fraction and gas velocity
dispersion. Galaxies in the sample visually classified as disc-like
are offset from the local stellar mass Tully-Fisher relation to higher
circular velocities, but this offset vanishes when both gas and stars
are included in the baryonic Tully-Fisher relation. The mean gas
velocity dispersion of the sample is ≃50km/s, and V/σ
ranges from 2 to 10 for most of the discs, similar to 'turbulent'
galaxies at high redshift. Half of our sample show disc-like rotation,
while ∼20 percent show no signs of rotation. The division between
rotating and non-rotating is approximately equal for the sub-samples
with either star formation rates >10M☉/yr, or specific star
formation rates typical of the star formation 'main sequence' at
z≃2. Across our whole sample, we find good correlation between the
dominance of `turbulence' in galaxy discs (as expressed by
V/σ) and gas fraction as has been predicted for marginally
stable Toomre discs. Comparing our sample with many others at low- and
high-redshift reveals a correlation between gas velocity dispersion
and star formation rate. These findings suggest the DYNAMO discs are
excellent candidates for local galaxies similar to turbulent z≃2 disc
galaxies.
Description:
We have selected a representative sample of 67 galaxies classified as
star forming in the Max-Planck-Institut fur Astrophysik and Johns
Hopkins University (MPA-JHU) value-added catalogue
(http://www.mpa-garching.mpg.de/SDSS/DR4/) of the Sloan Digital Sky
Survey (SDSS, York et al., 2000AJ....120.1579Y 2000AJ....120.1579Y).
Integral-field spectroscopic data were obtained using two different
telescopes; the 3.9m Anglo-Australian Telescope and the ANU
2.3m Telescope, both situated at Siding Spring Observatory,
Australia.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 48 13 Observing runs
table3.dat 108 68 SDSS target information
table4.dat 99 67 Basic and star formation properties of the sample
table5.dat 43 67 Kinematic properties of the sample
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See also:
II/267 : The SDSS Photometric Catalog, Release 4 (Adelman-McCarthy+, 2006)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Prog Program
11 A1 --- n_Prog [b] b: DD - Director's discretionary time
13- 23 A11 "date" Date Observation date
25- 29 F5.3 --- Moon Fraction of moon illuminated at mid-night
31- 48 A18 --- Weather Weather comments
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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- 4 A4 --- --- [SDSS]
6- 25 A20 --- Name Name, not always as a conventional SDSS name
27- 32 A6 --- SelID Selection ID (G1)
34- 51 I18 --- SpecObjId SDSS spectroscopic id number (1)
53- 63 A11 "date" Date Observation date
65- 74 A10 --- Inst Instrument
76- 79 I4 s Texp Total exposure time for the night (2)
81- 83 F3.1 arcsec Seeing ?=- Full width at half-maximum seeing
observed on a nearby star as part of
the observation sequence
85- 88 A4 --- --- [SDSS]
90-108 A19 --- SDSS Conventional SDSS name, as in Cat. II/267
(added by CDS)
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Note (1): The SDSS spectroscopic ID number from data release four
(Adelman-McCarthy et al. 2006ApJS..162...38A 2006ApJS..162...38A, Cat. II/267).
Note (2): See Section 3 for the lengths of individual exposures.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- SelID Selection ID (G1)
8- 14 F7.5 --- z Redshift (spectroscopic)
16- 20 F5.1 mag rMAG Absolute r-band magnitude
22- 26 F5.2 10+9Msun M* Stellar mass (1)
28- 32 F5.2 [10-7W] logLfHa Hα luminosity as measured by the Sloan
spectro-photometry from a 3arcsec diameter
fibre aperture
34- 38 F5.2 [10-7W] logLIHa Hα luminosity as measured by our IFU
observations in the masked region
(Section 4.1)
40- 43 F4.2 [10-7W] E_logLIHa Error on logLIHa (upper value)
45- 48 F4.2 [10-7W] e_logLIHa Error on logLIHa (lower value)
50- 54 F5.2 Msun/yr SFRB04 Star formation rate reported by Brinchmann
et al. (2004MNRAS.351.1151B 2004MNRAS.351.1151B) (2)
56- 60 F5.2 Msun/yr SFRHa Star formation rate measured from our IFU
observations, including a dust correction
(Section 5.2)
62- 65 F4.2 Msun/yr E_SFRHa Error on SFRHa (upper value)
67- 70 F4.2 Msun/yr e_SFRHa Error on SFRHa (lower value)
72- 76 F5.2 mag Ext Extinction of Hα due to dust
78- 81 F4.2 mag E_Ext Error on Ext (upper value)
83- 86 F4.2 mag e_Ext Error on Ext (lower value)
88- 92 F5.2 10+9Msun Mgas Gas mass (Section 5.3)
94- 98 F5.2 10+9Msun e_Mgas ? rms uncertainty on Mgas
99 A1 --- n_Mgas [i] i for ∞. These values are
effectively unconstrained because of the
inclination correction
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Note (1): The stellar mass of the object reproduced from Kauffmann et al.
(2003MNRAS.341...33K 2003MNRAS.341...33K). Their masses have been scaled by 0.88 to convert from
their Kroupa (2001MNRAS.322..231K 2001MNRAS.322..231K) initial mass function.
Note (2): These have been scaled by 0.88 to convert from their Kroupa
(2001MNRAS.322..231K 2001MNRAS.322..231K) initial mass function.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- SelID Selection ID (G1)
8- 11 F4.1 kpc rpr Radius from Petrosian r magnitude (rpetro,r)
13- 15 F3.1 kpc rer Exponential disc scale radius (rexp,r)
17- 20 F4.1 kpc rt ?=- Kinematic scale radius
22- 24 F3.1 kpc e_rt ? rms uncertainty on rt
26- 27 I2 deg i Inclination
30- 32 I3 km/s V2.2Rr ?=- Model velocity at a radius of 2.2 r-band
exponential disc scalelengths (3)
34- 35 I2 km/s e_V2.2Rr ? rms uncertainty on V2.2Rr
36 A1 --- n_V2.2Rr [s] s when Vshear/2 instead on V2.2Rr in
V2.2Rr column
38- 39 I2 km/s sigmac Velocity dispersion after removing velocity
shear larger than the spatial resolution
element (4)
41- 43 A3 --- Class Kinematic class (5)
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Note (3): For objects classified as CK and cCK, the value of Vshear/2
is shown in parenthesis instead of V2.2Rr.
Note (4): The statistical error on σm is typically 1-2km/s (see
Section 4.5).
Note (5): Classes are (see section 4.3):
RD = Rotating Disc
PR = Perturbed Rotator: the peak of the velocity dispersion is offset
from the centre of rotation by more than 3 kpc, or there is no
distinct peak.
CK = Complex Kinematics: galaxies that do not meet the criteria for RD or PR.
cRD = compact Rotating Disc (scale length <3kpc)
cPR = compact Perturbed Rotator (scale length <3kpc)
cCK = compact Complex Kinematics (scale length <3kpc)
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Note (G1): Selection ID as A NN-N (<[GGM2014] A NN-N> in Simbad).
Table 1: Target categories.
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Selection criteria
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Categories z Hα(a) nselected
A 0.055 < z < 0.084 65 < f < 140 7
B 0.055 < z < 0.084 140 < f < 300 10
C 0.055 < z < 0.084 300 < f < 930 9
D 0.055 < z < 0.084 930 < f 13
E 0.129 < z < 0.151 300 < f < 930 6
F 0.055 < z < 0.084 41.5 < L 7
G 0.129 < z < 0.151 930 < f 17
H z < 0.154 42.0 < L 1
I 0.174 < z 42.0 < L 0 (b)
Total 67
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Note (a): For a galaxy to be selected, its Hα emission was required to
meet either a flux range or a luminosity range in the MPA-JHU value-added
catalogue measurements of SDSS spectra. Flux requirements are denoted by
f and have units of 10-17erg/s/cm2, while luminosity requirements are
denoted by L and have units of log(erg/s).
Note (b): Although galaxies were selected in window I, none of them has been
observed at the time of writing. Window I is included for completeness
in subsequent papers of this series.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 10-Nov-2014