J/A+A/641/A118 Mean rest-UV spectra of Lyα emitters at z>3 (Feltre+, 2020)
The MUSE Hubble Ultra Deep Field Survey.
XV. The mean rest-UV spectra of Lyα emitters at z>3.
Feltre A., Maseda M.V., Bacon R., Pradeep J., Leclercq F., Kusakabe H.,
Wisotzki L., Hashimoto T., Schmidt K.B., Blaizot J., Brinchmann J.,
Boogaard L., Cantalupo S., Carton D., Inami H., Kollatschny W., Marino R.A.,
Matthee J., Nanayakkara T., Richard J., Schaye J., Tresse L., Urrutia T.,
Verhamme A., Weilbacher P.M.
<Astron. Astrophys. 641, A118 (2020)>
=2020A&A...641A.118F 2020A&A...641A.118F (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, spectra; Spectra, ultraviolet; Spectroscopy
Keywords: galaxies: evolution - galaxies: high-redshift - ISM: lines and bands -
ultraviolet: ISM - ultraviolet: galaxies
Abstract:
We investigate the ultraviolet (UV) spectral properties of faint
Lymanα emitters (LAEs) in the redshift range 2.9≤z≤4.6 and
provide material to prepare future observations of the faint Universe.
We use data from the MUSE Hubble Ultra Deep Survey to construct mean
rest-frame spectra of continuum-faint (median MUV of -18 and down to
MUV of -16), low stellar mass (median value of 108.4 and down
to 107 solar masses) LAEs at redshift z>3. We compute various averaged
spectra of LAEs sub-sampled on the basis of their observational (e.g.,
Lyα strength, UV magnitude and spectral slope) and physical
(e.g., stellar mass and star-formation rate) properties. We search for
UV spectral features other than Lyα, such as higher-ionization
nebular emission lines and absorption features. We successfully
observe the OIII]λ1666 and [CIII]λ1907+CIII]λ1909
collisionally excited emission lines and the HeIIλ1640
recombination feature, as well as the resonant CIVλ1548,1551
doublet either in emission or P-Cygni. We compare the observed
spectral properties of the different mean spectra and find the
emission lines to vary with the observational and physical properties
of the LAEs. In particular, the mean spectra of LAEs with larger
Lyα equivalent widths, fainter UV magnitudes, bluer UV spectral
slopes and lower stellar masses show the strongest nebular emission.
The line ratios of these lines are similar to those measured in the
spectra of local metal-poor galaxies, while their equivalent widths
are weaker compared to the handful of extreme values detected in
individual spectra of z>2 galaxies. This suggests that weak UV
features are likely ubiquitous in high z, low-mass and faint LAEs. We
publicly release the stacked spectra as they can serve as empirical
templates for the design of future observations, such as those with
the James Webb Space Telescope and the Extremely Large Telescope.
Description:
We present the unweighted mean stacked spectra of a sample of
2.9≤z≤4.6 LAEs selected from the MUSE Hubble Ultra Deep Survey.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 117 21 Details of the MUSE HUDF LAE subsamples and
emission-line EWs measured from the stacked
spectra
sp/* . 21 Individual stacked spectra
--------------------------------------------------------------------------------
See also:
J/A+A/608/A2 : MUSE Hubble Ultra Deep Field Survey. II (Inami+, 2017)
J/A+A/608/A8 : MUSE Hubble Ultra Deep Field Survey. VIII (Leclercq+, 2017)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- No [00/20] Reference number of the stacked
spectra
4- 40 A37 --- Subsamples Binning criterion of the LAE subsample
42- 44 I3 --- NLAE Number of LAEs in each subsample
46 A1 --- l_EWHeII Limit flag on EWHeII
47- 50 F4.2 0.1nm EWHeII ? HeIIλ1640 equivalent width (1)
52- 55 F4.2 0.1nm e_EWHeII ? HeIIλ1640 equivalent width error
57 A1 --- l_EWOIII] Limit flag on EWOIII]
58- 61 F4.2 0.1nm EWOIII] ? OIII]λ1666 equivalent width (1)
63- 66 F4.2 0.1nm e_EWOIII] ? OIII]λ1666 equivalent width error
68 A1 --- l_EW[SiIII] ? Limit flag on EW[SiIII]
69- 72 F4.2 0.1nm EW[SiIII] ? [SiIII]λ1883 equivalent width (1)
74- 77 F4.2 0.1nm e_EW[SiIII] ? [SiIII]λ1883 equivalent width error
79 A1 --- l_EW[CIII]07 Limit flag on EW[CIII]07
80- 83 F4.2 0.1nm EW[CIII]07 ? [CIII]λ1907 equivalent width (1)
85- 88 F4.2 0.1nm e_EW[CIII]07 ? [CIII]λ1907 equivalent width error
90 A1 --- l_EW[CIII]09 Limit flag on EW[CIII]09
91- 94 F4.2 0.1nm EW[CIII]09 ? [CIII]λ1909 equivalent width (1)
96- 99 F4.2 0.1nm e_EW[CIII]09 ? [CIII]λ1909 equivalent width error
102-117 A16 --- FileName Name of the file with the stacked spectra of
the subsample, in subdirectory sp
--------------------------------------------------------------------------------
Note (1): All EWs are rest frames.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: sp/*
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 F10.5 0.1nm lambda Wavelength in Angstroem
13- 21 F9.5 10-22W/m2/nm Flux Flux [10-20erg/s/cm/Å]
25- 32 F8.5 10-22W/m2/nm e_Flux Flux error
--------------------------------------------------------------------------------
Acknowledgements:
Anna Feltre, anna.feltre(at)inaf.it
References:
Bacon et al., Paper I 2017A&A...608A...1B 2017A&A...608A...1B
Inami et al., Paper II 2017A&A...608A...2I 2017A&A...608A...2I, Cat. J/A+A/608/A2
Brinchmann et al., Paper III 2017A&A...608A...3B 2017A&A...608A...3B
Maseda et al., Paper IV 2017A&A...608A...4M 2017A&A...608A...4M
Guerou et al., Paper V 2017A&A...608A...5G 2017A&A...608A...5G
Drake et al., Paper VI 2017A&A...608A...6D 2017A&A...608A...6D
Finley et al., Paper VII 2017A&A...608A...7F 2017A&A...608A...7F
Leclercq et al., Paper VIII 2017A&A...608A...8L 2017A&A...608A...8L, Cat. J/A+a/608/A8
Ventou et al., Paper IX 2017A&A...608A...9V 2017A&A...608A...9V
Hashimoto et al., Paper X 2017A&A...608A..10H 2017A&A...608A..10H
Boogaard et al., Paper XI 2018A&A...619A..27B 2018A&A...619A..27B
Feltre et al., Paper XII 2018A&A...617A..62F 2018A&A...617A..62F
Leclercq et al., Paper XIII 2020A&A...635A..82L 2020A&A...635A..82L
(End) Patricia Vannier [CDS] 02-Jul-2020