J-PLUS: Unveiling the brightest end of the Lyα luminosity function at 2.0 &lt; z &lt; 3.3 over 1000 deg<SUP>2</SUP>

Publication date: 
Main author: 
Spinoso, D.
IAA authors: 
Vílchez, J. M.
Spinoso, D.;Orsi, A.;López-Sanjuan, C.;Bonoli, S.;Viironen, K.;Izquierdo-Villalba, D.;Sobral, D.;Gurung-López, S.;Hernán-Caballero, A.;Ederoclite, A.;Varela, J.;Overzier, R.;Miralda-Escudé, J.;Muniesa, D. J.;Vílchez, J. M.;Alcaniz, J.;Angulo, R. E.;Cenarro, A. J.;Cristóbal-Hornillos, D.;Dupke, R. A.;Hernández-Monteagudo, C.;Marín-Franch, A.;Moles, M.;Sodré, L., Jr.;Vázquez-Ramió, H.
Astronomy and Astrophysics
Publication type: 
We present the photometric determination of the bright end of the Lyα luminosity function (LF; at L<SUB>Lyα</SUB> ≳ 10<SUP>43.3</SUP> erg s<SUP>-1</SUP>) within four redshift windows (∆ z &lt; 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 ∼1000 deg<SUP>2</SUP>, with limiting magnitude r​ ∼ ​22. The analysis of high-z Lyα-emitting sources over such a wide area is unprecedented and allows us to select approximately 14 500 hyper-bright (L<SUB>Lyα</SUB> &gt; 10<SUP>43.3</SUP> erg s<SUP>-1</SUP>) Lyα-emitting candidates. We test our selection with two spectroscopic programs at the GTC telescope, which confirm ∼89% of the targets as line-emitting sources, with ∼64% being genuine z​ ∼ ​2.2 quasars (QSOs). We extend the 2.2​ ≲ ​z​ ≲ ​3.3 Lyα LF for the first time above L<SUB>Lyα</SUB> ∼ 10<SUP>44</SUP> erg s<SUP>-1</SUP> and down to densities of ∼10<SUP>-8</SUP> Mpc<SUP>-3</SUP>. Our results unveil the Schechter exponential decay of the brightest-end of the Lyα LF in great detail, complementing the power-law component of previous determinations at 43.3 ≲ Log<SUB>10</SUB>(L<SUB>Lyα</SUB>/erg s<SUP>-1</SUP>) ≲ 44. We measure Φ<SUP>*</SUP> = (3.33 ± 0.19)×10<SUP>-6</SUP>, Log(L<SUP>*</SUP>) = 44.65 ± 0.65, and α = -1.35 ± 0.84 as an average over the probed redshifts. These values are significantly different from the typical Schechter parameters measured for the Lyα LF of high-z star-forming Lyman-α emitters (LAEs). This implies that z​ &gt; ​2 AGNs/QSOs (likely dominant in our samples) are described by a structurally different LF from that used to describe z​ &gt; ​2 star-forming LAEs, namely L<SUB>QSOs</SUB><SUP>*</SUP> ~ 100L<SUB>LAEs</SUB><SUP>*</SUP> and Φ<SUB>QSOs</SUB><SUP>*</SUP> ~ 10<SUP>-3</SUP> Φ<SUB>LAEs</SUB><SUP>*</SUP>, with the transition between the two LFs happening at L<SUB>Lyα</SUB> ∼ 10<SUP>43.5</SUP> erg s<SUP>-1</SUP>. This supports the scenario in which Lyα-emitting AGNs/QSOs are the most abundant class of z​ ≳ ​2 Lyα emitters at L<SUB>Lyα</SUB> ≳ 10<SUP>43.3</SUP> erg s<SUP>-1</SUP>. Finally, we suggest that a significant number of these z​ ≳ ​2 AGNs/QSOs (∼60% of our samples) are currently misclassified as stars based on their broad-band colours, but are identified for the first time as high-z line-emitters by our narrow-band-based selection. <P />Catalogs are available in electronic form both on the J-PLUS website at <A href='https://www.j-plus.es/ancillarydata/dr1_lya_emitting_candidates'>http://https://www.j-plus.es/ancillarydata/dr1_lya_emitting_candidates</A> and at the CDS via anonymous ftp to <A href='http://cdsarc.u-strasbg.fr/'>http://cdsarc.u-strasbg.fr</A> ( or via <A href='http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/643/A149'>http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/643/A149</A>
ADS Bibcode: 
galaxies: luminosity function;mass function;galaxies: high-redshift;quasars: emission lines;techniques: photometric;methods: observational;surveys;Astrophysics - Astrophysics of Galaxies;Astrophysics - Cosmology and Nongalactic Astrophysics