J/A+A/643/A149 J-PLUS Lyα-emitting candidates (Spinoso+, 2020)
J-PLUS: Unveiling the brightest-end of the Lyα luminosity function at
2.0 < z < 3.3 over 1000 deg2.
Spinoso D., Orsi A., Lopez-Sanjuan C., Bonoli S., Viironen K.,
Izquierdo-Villalba D., Sobral D., Gurung-Lopez S., Hernan-Caballero A.,
Ederoclite A., Varela J., Overzier R., Miralda-Escude J., Muniesa D.J.,
Vilchez J.M., Alcaniz J., Angulo R.E., Cenarro A.J., Cristobal-Hornillos D.,
Dupke R.A., Hernandez-Monteagudo C., Marin-Franch A., Moles M., Sodre L.Jr,
Vazquez-Ramio H.
<Astron. Astrophys. 643, A149 (2020)>
=2020A&A...643A.149S 2020A&A...643A.149S (SIMBAD/NED BibCode)
ADC_Keywords: Galaxy catalogs ; Ultraviolet ; Equivalent widths
Keywords: galaxies: luminosity function, mass function -
galaxies: high-redshift - quasars: emission lines -
techniques: photometric - methods: observational - surveys
Abstract:
We present the photometric determination of the bright-end of the
Lyα luminosity function (at LLyα≳1043.5erg/s) within
four redshifts windows (Δz<0.16) in the interval 2.2≲z≲3.3. Our
work is based on the Javalambre Photometric Local Universe Survey
(J-PLUS) first data-release, which provides multiple narrow-band
measurements over ∼1000deg2, with limiting magnitude ∼22.
Theanalysis of high-z Lyα-emitting sources over such a wide area
is unprecedented, and allows to select a total of ∼14500
hyper-bright(LLyα>1043.3erg/s) Lyα-emitting
candidates. We test our selection with two spectroscopic follow-up
programs at the GTC telescope,which confirm as line-emitting sources
∼89% of the targets, with ∼64% being genuine z∼2.2 QSOs. We extend the
2.2≲z≲3.3 Lyα luminosity function for the first time above
LLyα∼1044erg/s and down to densities of ∼10-8Mpc-3. Our
results unveil with high detail the Schechter exponential-decay of the
brightest-end of the Lyα LF, complementing the power-law
component of previous LF determinations at
43.3≲Log10(LLyα/(erg/s))≲44. We measure
{PHI}*=(3.33±0.19)x10-6, Log(L*)=44.65±0.65 and
α=-1.35±0.84 as an average over the redshifts we probe. These
values are significantly different than the typical Schechter
parameters measured for the Lyα LF of high-z star-forming LAEs.
This suggests that z>2 AGN/QSOs (likely dominant in our samples) are
described by a structurally different LF than z>2 star-forming LAEs,
namely with L*QSOs∼100 L*LAEs and {PHI}*QSOs∼10-3{PHI}*LAEs.
Finally, our method identifies very efficiently as high-z
line-emitters sources without previous spectroscopic confirmation,
currently classified as stars (∼2000 objects in each redshift bin, on
average). Assuming a large predominance of Lyα-emitting AGN/QSOs
in our samples, this supports the scenario by which these are the most
abundant class of z≳2 Lyα emitters at
LLyα≳1043.3erg/s.
Description:
These four lists contain sources selected as genuine Lyman-alpha
emitting candidates by the methodology detailed in the paper. In
brief, the J-PLUS narrow-bands J0395, J0410, J0430 and J0515 were used
to detect photometric excesses of sources within the DR1 dual-mode
(i.e. r-band selected) parent sample. This excess and its significance
was estimated by using the method detailed in Vilella-Rojo et al.
(2015A&A...580A..47V 2015A&A...580A..47V) and discussed in Logrono-Garcia et al.
(2019A&A...622A.180L 2019A&A...622A.180L). Each of the four NBs were used to target
Lyman-alpha emission, respectively at redshift z=2.2, z=2.4, z=2.5 and
z=3.2. After the first selection based on the NB-excess significance
of each source, the resulting lists of objects were cleaned from the
presence of known interlopers, namely low-z galaxies, stars and
AGN/QSOs outside the redshift intervals probed by the narrow-bands for
Lyman-alpha emission. All the above steps are extensively detailed in
the paper. The four lists presented here include only the genuine
Lyα-emitting candidates used to compute the luminosity functions
presented in the paper. These candidates are defined as the sources
selected on the basis of their reliable NB excess, which do not
present any identification as known low-z interlopers. We stress that
genuine candidates include the Lyα-emitting QSOs belonging to
the SDSS spectroscopic sample (Paris et al., 2018A&A...613A..51P 2018A&A...613A..51P, Cat.
VII/286), whose redshift is compatible to Lyα-emission in the
wavelength ranges probed by each narrow-band. See paper for further
details about the selection procedures.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
cj0395.dat 128 2547 LAE candidates DR1, in narrow-band J0395
cj0410.dat 128 5556 LAE candidates DR1, in narrow-band J0410
cj0430.dat 128 4994 LAE candidates DR1, in narrow-band J0430
cj0515.dat 128 1467 LAE candidates DR1, in narrow-band J0515
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See also:
http://archive.cefca.es/catalogues/jplus-dr1 : J-PLUS-DR1 Home Page
Byte-by-byte Description of file: cj0395.dat cj0410.dat cj0430.dat cj0515.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- TileId Identifier of the Tile image where the object
was detected (TILE_ID)
7- 11 I5 --- Id Number identifier assigned by Sextractor for
the object in the image (NUMBER)
13- 22 F10.6 deg RAdeg Right ascension (J2000) (ALPHA_J2000)
24- 33 F10.6 deg DEdeg Declination (J2000) (DELTA_J2000)
35- 46 E12.6 mW/m2 FLya Photometric estimate of the integrated
line-flux in Lyα, corrected for
filter-width losses (LYA_FLUX)
48- 59 E12.6 mW/m2 e_FLya Error on FLya (LYAFLUXERR)
61- 72 E12.6 10-7W LLya ? Lyα luminosity computed from the
sources FLya and redshift (LYA_LUM)
74- 85 E12.6 10-7W e_LLya ? Error on LLya (LYALUMERR)
87- 98 E12.6 0.1nm EWLya Lyα equivalent width (LYA_EW) (1)
100-107 F8.6 --- z Sources redshift assuming detection at the
narrow-band central wavelength (Z) (2)
109-118 F10.6 --- e_z ?=-1 Redshift error (Z_ERR) (3)
120 I1 --- SDSS-QSO [0/1] Flag identifying the presence of
SDSS QSOs counterparts (at any z)
(SDSS_QSO) (4)
122 I1 --- SDSS-QSORz [0/1] Flag identifying the presence of
SDSS QSOs counterparts (at the redshift
sampled by the NB used to select the
candidates) (SDSSRIGHTzQSO) (4)
124 I1 --- LQAC-QSO [0/1] Flag identifying the presence of LQAC
(Souchay et al., 2015, Cat. J/A+A/583/75)
QSOs counterparts (at any z) (LQAC_QSO) (4)
126 I1 --- WISE-QSO [0/1] Flag identifying the presence of
counterparts in the allWISE catalog (Wright
et al. 2010, Cat. II/328) (WISE_QSO) (5)
128 I1 --- XRAY [0/1] Flag identifying the presence of X-ray
counterparts in the 2RXS and XMMSLEW2
catalogs (Salvato et al., 2018,
Cat. J/MNRAS/473/4937) (XRAY_SOURCE) (4)
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Note (1): EW=FLya/NB_continuum, where NB_continuum is computed with the method
of Vilella-Rojo et al. (2015A&A...580A..47V 2015A&A...580A..47V).
Note (2): For objects with SDSS counterpart, 'z' is equal to the SDSS zspec
(Paris et al., 2018A&A...613A..51P 2018A&A...613A..51P, Cat. VII/286).
Note (3): namely half of the narrow-band FWHM for sources without SDSS
counterparts, otherwise e_z is the value given by SDSS (see Paris et al.,
2018A&A...613A..51P 2018A&A...613A..51P, Cat. VII/286 for details).
Note (4): 0 if no counterparts.
Note (5): with WISE colors compatible with QSO color locus (namely W1-W2>0.5,
see e.g. Chhetri et al., 2020MNRAS.494..923C 2020MNRAS.494..923C). 0 if no counterparts.
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Acknowledgements:
Daniele Spinoso, dspinoso(at)cefca.es
(End) Patricia Vannier [CDS] 15-Sep-2020