J/ApJ/847/38 Extreme emission line galaxies at z≲0.05 (Yang+, 2017)
Blueberry galaxies: the lowest mass young starbursts.
Yang H., Malhotra S., Rhoads J.E., Wang J.
<Astrophys. J., 847, 38-38 (2017)>
=2017ApJ...847...38Y 2017ApJ...847...38Y (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, spectra ; Redshifts ; Photometry, SDSS ;
Equivalent widths
Keywords: galaxies: dwarf; galaxies: high-redshift; galaxies: ISM;
galaxies: starburst; galaxies: star formation; H II regions
Abstract:
Searching for extreme emission line galaxies allows us to find
low-mass metal-poor galaxies that are good analogs of high redshift
Lyα emitting galaxies. These low-mass extreme emission line
galaxies are also potential Lyman-continuum leakers. Finding them at
very low redshifts (z≲0.05) allows us to be sensitive to even lower
stellar masses and metallicities. We report on a sample of extreme
emission line galaxies at z≲0.05 (blueberry galaxies). We selected
them from SDSS broadband images on the basis of their broadband colors
and studied their properties with MMT spectroscopy. From the entire
SDSS DR12 photometric catalog, we found 51 photometric candidates. We
spectroscopically confirm 40 as blueberry galaxies.
These blueberries are dwarf starburst galaxies with very small sizes
(<1kpc) and very high ionization ([OIII]/[OII]∼10-60). They also have
some of the lowest stellar masses (log(M/M☉)∼6.5-7.5) and lowest
metallicities (7.1<12+log(O/H)<7.8) of starburst galaxies. Thus, they
are small counterparts to green pea galaxies and high redshift
Lyα emitting galaxies.
Description:
We obtained spectra of SDSS-DR12 candidates sample from SDSS, MMT,
and LBT.
Out of the total sample of 51 sources, 10 sources already have SDSS
spectra.
One object was observed using LBT/MODS (5-minute exposure) in the
morning of 2016 May 07.
Another 36 objects were observed with MMT/BlueChannel on 2017 Jan 07.
The remaining four objects do not have optical spectra.
In all spectra, the wavelength range of [OII]3727 to Hα was
covered. Out of the 47 objects with spectra, 40 objects show extreme
emission lines.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table12.dat 389 40 The blueberry galaxies properties (tables 1 and 2)
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See also:
II/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers+, 2016)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
J/ApJ/844/171 : Lyα profile in 43 Green Pea galaxies (Yang+, 2017)
J/A+A/599/A76 : L-σ relation for HII galaxies (Melnick+, 2017)
J/ApJ/819/110 : Extremely metal-poor gal. in SDSS. II. (Sanchez Almeida+ 2016)
J/ApJ/803/34 : z∼4-10 galaxies from HST legacy fields (Bouwens+, 2015)
J/ApJ/765/140 : Stacked spectra of SDSS star forming galaxies (Andrews+, 2013)
J/AJ/143/145 : Emission-line objects from ALFALFA (Kellar+, 2012)
J/AJ/143/133 : Properties of dwarf galaxies from ALFALFA survey (Huang+, 2012)
J/ApJ/725/394 : High-redshift Lyα emitters (Hu+, 2010)
J/AJ/139/279 : Outlying HII regions in HI-selected galaxies (Werk+, 2010)
J/ApJ/706/599 : Hα and UV SFR in the local volume (Lee+, 2009)
J/A+A/448/955 : Abundances of emission galaxies in SDSS-DR3 (Izotov+, 2006)
J/ApJS/147/29 : BRHalpha data of blue compact dwarf gal. (Gil De Paz+, 2003)
Byte-by-byte Description of file: table12.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Seq [2/122] Object ID
5- 14 F10.6 deg RAdeg Right Ascension (J2000)
16- 24 F9.6 deg DEdeg Declination (J2000)
26- 33 F8.6 --- zspec [0.02/0.06] Redshift,
from optical spectra
35- 38 A4 --- Tel Telescope used for getting
optical spectra
40- 45 F6.4 mag E(B-V)MW [0.006/0.4] Milky Way extinction,
Schlafly & Finkbeiner
(2011ApJ...737..103S 2011ApJ...737..103S)
47- 51 F5.2 mag u-SDSS [18.3/22.5] Magnitude,
SDSS u-band cModelMag
53- 57 F5.2 mag g-SDSS [17.3/21.4] Magnitude,
SDSS g-band cModelMag
59- 63 F5.2 mag r-SDSS [18/22.1] Magnitude,
SDSS r-band cModelMag
65- 69 F5.2 mag i-SDSS [18.2/22] Magnitude,
SDSS i-band cModelMag
71- 75 F5.2 mag z-SDSS [18/21.6] Magnitude,
SDSS z-band cModelMag
77- 80 F4.2 mag e_u-SDSS [0.02/0.7] Error on u-SDSS
82- 85 F4.2 mag e_g-SDSS [0.01/0.06] Error on g-SDSS
87- 90 F4.2 mag e_r-SDSS [0.01/0.2] Error on r-SDSS
92- 95 F4.2 mag e_i-SDSS [0.01/0.2] Error on i-SDSS
97-100 F4.2 mag e_z-SDSS [0.04/0.8] Error on z-SDSS
102-106 F5.2 mag g-PS1 [17.3/21.4] Magnitude,
PANSTARRS1 g-band KronMag
108-112 F5.3 mag e_g-PS1 [0.003/0.06] Error on g-PS1
114-118 F5.2 mag r-PS1 [17.8/22.1] Magnitude,
PANSTARRS1 r-band KronMag
120-124 F5.3 mag e_r-PS1 [0.005/0.2] Error on r-PS1
126-130 F5.2 mag i-PS1 [18.3/22.1] Magnitude,
PANSTARRS1 i-band KronMag
132-136 F5.3 mag e_i-PS1 [0.007/0.2] Error on i-PS1
138-144 F7.2 mag z-PS1 [18.5/22.1]?=-999 Magnitude,
PANSTARRS1 z-band KronMag
146-152 F7.2 mag e_z-PS1 [0.01/0.2]?=-999 Error on z-PS1
154-160 F7.2 mag y-PS1 [18/22]?=-999 Magnitude,
PANSTARRS1 y-band KronMag
162-168 F7.2 mag e_y-PS1 [0.02/0.5]?=-999 Error on y-PS1
170-172 F3.1 [Msun] Mass [6.6/8.6] Stellar mass (log(M/Msun))
174-180 F7.3 --- 12+log(O/H) [7/8]?=-99 Gas metallicity,
12+log(O/H)
182-188 F7.3 --- e_12+log(O/H) [0.001/0.2]?=-99 error on 12+log(O/H)
190-194 F5.3 Msun/yr SFR [0.04/1.7] Star formation rate from
Hβ luminosity
196-202 F7.3 10-16mW/m2 [OII]3727 [1/124]?=-99 Flux, [OII]3727,
in units of 10-16erg/s/cm^2
204-210 F7.3 10-16mW/m2 e_[OII]3727 [0.01/5.2]?=-99 Error on [OII]3727
212-218 F7.3 10-16mW/m2 [NeIII]3869 [1/126] Flux, [NeIII]3869,
in units of 10-16erg/s/cm^2
220-224 F5.3 10-16mW/m2 e_[NeIII]3869 [0.01/3.5] Error on [NeIII]3869
226-232 F7.3 10-16mW/m2 Hdelta [0.6/64.1] Flux, Hδ,
in units of 10-16erg/s/cm^2
234-238 F5.3 10-16mW/m2 e_Hdelta [0.005/1.1] Error on Hδ
240-246 F7.3 10-16mW/m2 Hgamma [0.6/64.1] Flux, Hγ,
in units of 10-16erg/s/cm^2
248-252 F5.3 10-16mW/m2 e_Hgamma [0.005/1.1] Error on Hγ
254-259 F6.3 10-16mW/m2 [OIII]4363 [0.4/40] Flux, [OIII]4363,
in units of 10-16erg/s/cm^2
261-266 F6.3 10-16mW/m2 e_[OIII]4363 [0.006/2.6] Error on [OIII]4363,
268-274 F7.3 10-16mW/m2 Hbeta [0.3/281] Flux, Hβ,
in units of 10-16erg/s/cm^2
276-280 F5.3 10-16mW/m2 e_Hbeta [0.001/1] Error, Hβ,
282-289 F8.3 10-16mW/m2 [OIII]4959 [0.8/642] Flux, [OIII]4959,
in units of 10-16erg/s/cm^2
291-295 F5.3 10-16mW/m2 e_[OIII]4959 [0.001/6] Error on [OIII]4959,
297-304 F8.3 10-16mW/m2 [OIII]5007 [2.4/1941] Flux, [OIII]5007,
in units of 10-16erg/s/cm^2
306-311 F6.3 10-16mW/m2 e_[OIII]5007 [0.001/79] Error on [OIII]5007,
313-320 F8.3 10-16mW/m2 Halpha [0.8/878.8] Flux, Hα,
in units of 10-16erg/s/cm^2
(2.86*Hbeta fluxes) (1)
322-326 F5.3 10-16mW/m2 e_Halpha [0] Error on Hα (always "0.000")
(1)
328-332 F5.1 0.1nm EW(OII) [8/125]?=-99 restframe equivalent
width, [OII]3727
334-338 F5.1 0.1nm EW(Hbeta) [29/338] restframe equivalent
width, Hβ
340-343 F4.1 0.1nm e_EW(Hbeta) [3.9/36.3] Error on EW(Hβ)
345-350 F6.1 0.1nm EW(OIII) [202/2636] restframe equivalent width,
[OIII]5007
352-356 F5.1 0.1nm e_EW(OIII) [26/305] Error on EW([OIII]5007)
358-362 F5.1 0.1nm EW(Halpha) [29/338] restframe equivalent width,
Hα (values identical to EW(Hb))
(1)
364-373 F10.6 deg RANdeg Right Ascension of nearest neighbor
in SDSS spectroscopic catalog (J2000)
375-383 F9.6 deg DENdeg Declination of nearest neighbor in
SDSS spectroscopic catalog (J2000)
385-389 I5 Mpc Sep [303/25337] 3D distance to the nearest
neighbor in SDSS-DR12 spectroscopic
catalog
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Note (1): There are no Halpha measurements from the spectra. Those values will
not be included in VizieR.
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Acknowledgements:
Huan YANG [Arizona State University;
University of Science and Technology of China]
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 29-May-2018