J/MNRAS/442/3565 L-σ relation for massive star formation (Chavez+, 2014)
The L-σ relation for massive bursts of star formation.
Chavez R., Terlevich R., Terlevich E., Bresolin F., Melnick J., Plionis M.,
Basilakos S.
<Mon. Not. R. Astron. Soc., 442, 3565-3597 (2014)>
=2014MNRAS.442.3565C 2014MNRAS.442.3565C
ADC_Keywords: Galaxies, spectra ; H II regions ; Equivalent widths
Keywords: HII regions - galaxies: general - cosmology: observations -
distance scale
Abstract:
The validity of the emission-line luminosity versus ionized gas
velocity dispersion (L-σ) correlation for HII galaxies (HIIGx)
and its potential as an accurate distance estimator are assessed. For
a sample of 128 local (0.02≲z≲0.2) compact HIIGx with high
equivalent widths of their Balmer emission lines, we obtained the
ionized gas velocity dispersion from high signal-to-noise ratio (S/N)
high-dispersion spectroscopy (Subaru High Dispersion Spectrograph
(HDS) and European Southern Observatory (ESO) Very Large Telescope
Ultraviolet and Visual Echelle Spectrograph (VLT-UVES)) and integrated
Hβ fluxes from low-dispersion wide aperture spectrophotometry. We
find that the L(Hβ)-σ relation is strong and stable against
restrictions in the sample (mostly based on the emission-line
profiles). The `Gaussianity' of the profile is important for reducing
the root-mean-square (rms) uncertainty of the distance indicator, but
at the expense of substantially reducing the sample. By fitting other
physical parameters into the correlation, we are able to decrease the
scatter significantly without reducing the sample. The size of the
star-forming region is an important second parameter, while adding the
emission-line equivalent width or the continuum colour and metallicity
produces the solution with the smallest rms
scatter=δlogL(Hβ)=0.233. The derived coefficients in the
best L(Hβ)-σ relation are very close to what is expected
from virialized ionizing clusters, while the derived sum of the
stellar and ionized gas masses is similar to the dynamical mass
estimated using the Hubble Space Telescope (HST) corrected Petrosian
radius. These results are compatible with gravity being the main
mechanism causing the broadening of the emission lines in these very
young and massive clusters. The derived masses range from about
2x106M☉ to 109M☉ and their 'corrected' Petrosian
radius ranges from a few tens to a few hundred pc.
Description:
We observed 128 HIIGx selected from the SDSS DR7 spectroscopic
catalogue (Abazajian et al., 2009ApJS..182..543A 2009ApJS..182..543A) for having the
strongest emission lines relative to the continuum (i.e. largest
equivalent widths) and in the redshift range 0.01<z<0.2.
The low-resolution spectroscopy was performed with two identical
Boller & Chivens Cassegrain spectrographs (B&C) in long-slit mode at
similar 2-m class telescopes, one of them at the Observatorio
Astronomico Nacional (OAN) in San Pedro Martir (Baja California) and
the other one at the Observatorio Astrofisico Guillermo Haro (OAGH)
in Cananea (Sonora), both in Mexico.
High spectral resolution spectroscopy was obtained using echelle
spectrographs at 8-m class telescopes. The telescopes and instruments
used are UVES at the ESO VLT in Paranal, Chile and the HDS at the
National Astronomical Observatory of Japan (NAOJ) Subaru Telescope in
Mauna Kea, Hawaii.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 65 8 Journal of observations
table5.dat 71 128 FWHM of Hβ and [OIII]λ5007 from the
high-resolution spectra
table3.dat 96 128 Low-resolution and SDSS DR7 Hβ and
[OIII] λλ4959,5007 fluxes and
EW(Hβ)
table4.dat 131 128 Line-intensity ratios with respect to
Hβ=100 (our measurements from SDSS DR7)
table6.dat 140 128 Derived values for the HII galaxies sample
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See also:
II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- Dates Observation dates
18- 28 A11 --- Tel Telescope: ESO-VLT, NOAJ-Subaru, OAGH-2.12m
or OAN-2
30- 37 A8 --- Inst Instrument: B&C, HDS or UVES-Red
39- 58 A20 --- Det Detector
59 A1 --- n_Det [a] a: 2x4 binning
61- 65 F5.2 arcsec Slit [2/13.1] Slit width
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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- 3 I3 --- Seq [1/128] Sequential number
5- 19 A15 --- Name Galaxy Name (JHHMMSS+DDMMSS)
20- 28 F9.5 deg RAdeg Right ascension (J2000)
30- 38 F9.5 deg DEdeg Declination (J2000)
40- 46 F7.5 --- zh [0.009/0.2] Heliocentric redshift from SDSS-DR7
48- 51 F4.2 10-5 e_zh rms uncertainty on z
53- 56 F4.2 0.1nm W(Hb) [0.57/3.62]?=- Hβ FWHM
58- 61 F4.2 0.1nm e_W(Hb) [0.03/0.23]?=- rms uncertainty on W(Hb)
63- 66 F4.2 0.1nm W(5007) [0.63/3.24]?=- [OIII]λ5007 FWHM
68- 71 F4.2 0.1nm e_W(5007) [0/0.22]?=- rms uncertainty on W(5007)
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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- 3 I3 --- Seq [1/128] Sequential number
5- 19 A15 --- Name Galaxy Name (JHHMMSS+DDMMSS)
20- 25 F6.1 10-19W/m2 F(Hb) SDSS DR7 Hβ flux (10-16erg/cm2/s)
27- 29 F3.1 10-19W/m2 e_F(Hb) rms uncertainty on F(Hb)
31- 36 F6.1 10-19W/m2 F(Hb)g Gaussian (peak) fit Hβ flux
38- 42 F5.1 10-19W/m2 e_F(Hb)g rms uncertainty on F(Hb)g
44- 49 F6.1 10-19W/m2 F(Hb)i Integral Hβ flux
51- 55 F5.1 10-19W/m2 e_F(Hb)i rms uncertainty on F(Hb)i
57- 62 F6.1 10-19W/m2 F(4959) ?=- Gaussian fit (peak) flux of
[OIII]λ4959 line
64- 68 F5.1 10-19W/m2 e_F(4959) ? rms uncertainty on F(4959)
70- 76 F7.1 10-19W/m2 F(5007) ?=- Gaussian fit (peak) flux of
[OIII]λ5007 line
78- 83 F6.1 10-19W/m2 e_F(5007) ? rms uncertainty on F([OIII]2)
85- 89 F5.1 0.1nm EW(Hb) Hβ equivalent width (Å)
91- 94 F4.1 0.1nm e_EW(Hb) rms uncertainty on EW(Hb)
96 I1 --- Inst [1/3] Origin of the fluxes and EWs (1)
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Note (1): The instrument flag indicates the origin of the data as follows:
1 = Directly measured using long slit as described in the text
2 = from aperture-corrected SDSS DR7 measurements
3 = from Terlevich et al. 1991 (J/A+AS/91/285); in this case errors
in fluxes and EW are taken directly from the cited source.
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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- 3 I3 --- Seq [1/128] Sequential number
5- 19 A15 --- Name Name (JHHMMSS+DDMMSS)
20- 24 F5.1 % I3726 ?=- [OII]λ3726/Hβ intensity ratio
26- 29 F4.1 % e_I3726 ?=- rms uncertainty on I3726
31- 35 F5.1 % I3729 ?=- [OII]λ3729/Hβ intensity ratio
37- 40 F4.1 % e_I3729 ?=- rms uncertainty on I3729
42- 46 F5.2 % I4363 ?=- [OIII]λ4363/Hβ intensity ratio
48- 51 F4.1 % e_I4363 ?=- rms uncertainty on I4363
53- 55 I3 % I4959 ?=- [OIII]λ4959/Hβ intensity ratio
57- 60 F4.1 % e_I4959 ?=- rms uncertainty on I4959
62- 64 I3 % I5007 ?=- [OIII]λ5007/Hβ intensity ratio
66- 69 F4.1 % e_I5007 ?=- rms uncertainty on I5007
71- 74 F4.1 % Hg ?=- Hγ/Hβ intensity ratio
76- 79 F4.1 % e_Hg ?=- rms uncertainty on Hγ
81- 83 I3 % Ha ?=- Hα/Hβ intensity ratio
85- 88 F4.1 % e_Ha ?=- rms uncertainty on Hα
90- 95 F6.2 % I6548 ?=- [NII]λ6548/Hβ intensity ratio
97-100 F4.1 % e_I6548 ?=- rms uncertainty on I6548
102-106 F5.1 % I6584 ?=- [NII]λ6584/Hβ intensity ratio
108-111 F4.1 % e_I6584 ?=- rms uncertainty on I6584
113-116 F4.1 % I6716 ?=- [SII]λ6716/Hβ intensity ratio
118-121 F4.1 % e_I6716 ?=- rms uncertainty on I6716
123-126 F4.1 % I6731 ?=- [SII]λ6731/Hβ intensity ratio
128-131 F4.1 % e_I6731 ?=- rms uncertainty on I6731
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [1/128] Sequential number
5 I1 --- Sam [1/4] Sample flag (2)
7- 13 F7.5 --- z [0.009/0.2] Our heliocentric redshift,
corrected from bulk flow effects
15- 18 F4.2 10-5 e_z rms uncertainty on z
20- 23 F4.2 mag AV [0/1.9] Absorption in V band
25- 28 F4.2 mag e_AV [0/0.8] rms uncertainty on AV
30- 34 F5.2 % Q [0/33] Ratio between the equivalent widths
of Hβ in absorption and in emission.
36- 39 F4.2 --- cHb [0/0.18] Balmer decrement
41- 44 F4.2 --- e_cHb [0/0.08] rms uncertainty on cHb
46- 50 F5.3 [km/s] logsHb [1.1/1.9]?=- Hβ velocity dispersion
52- 56 F5.3 [km/s] e_logsHb [0.04/0.06]? rms uncertainty on logsigHb
58- 62 F5.3 [km/s] logsO [1.1/1.9]?=- [OIII] velocity dispersion
64- 68 F5.3 [km/s] e_logsO [0/0.04]? rms uncertainty on logsig[OIII]
70- 74 F5.2 [10-7W] logLHb [39.5/42.5] Corrected Hβ luminosity
76- 79 F4.2 [10-7W] e_logLHb [0.03/0.33] rms uncertainty on logL(Hβ)
81- 84 F4.2 [-] Ab(O) [7.6/8.4]?=- Total oxygen abundance
Ab(O)=12+log(O/H)
86- 89 F4.2 [-] e_Ab(O) [0.05/0.4]? rms uncertainty on Ab(O)
91- 94 F4.2 [pc] logRu [2/3.4]?=- Seeing-corrected Petrosian radius
96- 99 F4.2 [pc] e_logRu ? rms uncertainty on logRu
101-104 F4.2 [Msun] logMdyn [6.9/9.3]?=- Dynamical mass
106-109 F4.2 [Msun] e_logMdyn [0.04/0.17]? rms uncertainty on logMdyn
111-114 F4.2 [Msun] logMcl [6.3/9.4]?=- Photometric mass of the
ionizing clusters
116-119 F4.2 [Msun] e_logMcl [0.03/0.33]? rms uncertainty on logMcl
121-124 F4.2 [Msun] logMion [5.1/8.1]?=- Photometric mass of ionized gas
126-129 F4.2 [Msun] e_logMion [0.05/0.2]? rms uncertainty on logMion
131-135 F5.2 [Msun/yr] logSFR [-1.3/1.7] Star formation rate
137-140 F4.2 [Msun/yr] e_logSFR [0.03/0.33] rms uncertainty on logSFR
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Note (2): The number indicates that the object belongs to a given sample and to
the samples up in the hierarchy, e.g.
4 indicates membership of S4 but also of S3, S2 and S1, whereas
3 indicates membership of S3, S2 and S1, etc.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 05-Mar-2015