The Pan-STARRS1 z > 5.6 Quasar Survey. III. The z ≈ 6 Quasar Luminosity Function
We present the z ≈ 6 type-1 quasar luminosity function (QLF), based on the Pan-STARRS1 (PS1) quasar survey. The PS1 sample includes 125 quasars at z ≈ 5.7–6.2, with −28 ≲ M _1450 ≲ −25. With the addition of 48 fainter quasars from the SHELLQs survey, we evaluate the z ≈ 6 QLF over −28 ≲ M _1450 ≲ −2...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/aca7ca |
| _version_ | 1797695612713435136 |
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| author | Jan-Torge Schindler Eduardo Bañados Thomas Connor Roberto Decarli Xiaohui Fan Emanuele Paolo Farina Chiara Mazzucchelli Riccardo Nanni Hans-Walter Rix Daniel Stern Bram P. Venemans Fabian Walter |
| author_facet | Jan-Torge Schindler Eduardo Bañados Thomas Connor Roberto Decarli Xiaohui Fan Emanuele Paolo Farina Chiara Mazzucchelli Riccardo Nanni Hans-Walter Rix Daniel Stern Bram P. Venemans Fabian Walter |
| author_sort | Jan-Torge Schindler |
| collection | DOAJ |
| description | We present the z ≈ 6 type-1 quasar luminosity function (QLF), based on the Pan-STARRS1 (PS1) quasar survey. The PS1 sample includes 125 quasars at z ≈ 5.7–6.2, with −28 ≲ M _1450 ≲ −25. With the addition of 48 fainter quasars from the SHELLQs survey, we evaluate the z ≈ 6 QLF over −28 ≲ M _1450 ≲ −22. Adopting a double power law with an exponential evolution of the quasar density (Φ( z ) ∝ 10 ^k ^( ^z ^−6) ; k = −0.7), we use a maximum likelihood method to model our data. We find a break magnitude of ${M}^{* }=-{26.38}_{-0.60}^{+0.79}\,\mathrm{mag}$ , a faint-end slope of $\alpha =-{1.70}_{-0.19}^{+0.29}$ , and a steep bright-end slope of $\beta =-{3.84}_{-1.21}^{+0.63}$ . Based on our new QLF model, we determine the quasar comoving spatial density at z ≈ 6 to be $n({M}_{1450}\lt -26)={1.16}_{-0.12}^{+0.13}\,{\mathrm{cGpc}}^{-3}$ . In comparison with the literature, we find the quasar density to evolve with a constant value of k ≈ −0.7, from z ≈ 7 to z ≈ 4. Additionally, we derive an ionizing emissivity of ${\epsilon }_{912}(z=6)={7.23}_{-1.02}^{+1.65}\times {10}^{22}\,\mathrm{erg}\,{{\rm{s}}}^{-1}\,{\mathrm{Hz}}^{-1}\,{\mathrm{cMpc}}^{-3}$ , based on the QLF measurement. Given standard assumptions, and the recent measurement of the mean free path by Becker et al. at z ≈ 6, we calculate an H i photoionizing rate of Γ _H I ( z = 6) ≈ 6 × 10 ^−16 s ^−1 , strongly disfavoring a dominant role of quasars in hydrogen reionization. |
| first_indexed | 2024-03-12T03:14:48Z |
| format | Article |
| id | doaj.art-1b15ea404cb24d26962d6f45af98a30a |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T03:14:48Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
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| series | The Astrophysical Journal |
| spelling | doaj.art-1b15ea404cb24d26962d6f45af98a30a2023-09-03T14:11:16ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0194316710.3847/1538-4357/aca7caThe Pan-STARRS1 z > 5.6 Quasar Survey. III. The z ≈ 6 Quasar Luminosity FunctionJan-Torge Schindler0https://orcid.org/0000-0002-4544-8242Eduardo Bañados1https://orcid.org/0000-0002-2931-7824Thomas Connor2https://orcid.org/0000-0002-7898-7664Roberto Decarli3https://orcid.org/0000-0002-2662-8803Xiaohui Fan4https://orcid.org/0000-0003-3310-0131Emanuele Paolo Farina5https://orcid.org/0000-0002-6822-2254Chiara Mazzucchelli6https://orcid.org/0000-0002-5941-5214Riccardo Nanni7https://orcid.org/0000-0002-2579-4789Hans-Walter Rix8https://orcid.org/0000-0003-4996-9069Daniel Stern9https://orcid.org/0000-0003-2686-9241Bram P. Venemans10https://orcid.org/0000-0001-9024-8322Fabian Walter11https://orcid.org/0000-0003-4793-7880Max Planck Institut für Astronomie , Königstuhl 17, D-69117, Heidelberg, Germany ; schindler@strw.leidenuniv.nl; Leiden Observatory, Leiden University , P.O. Box 9513, 2300 RA Leiden, The NetherlandsMax Planck Institut für Astronomie , Königstuhl 17, D-69117, Heidelberg, Germany ; schindler@strw.leidenuniv.nlJet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive, Pasadena, CA 91109, USA; Center for Astrophysics | Harvard & Smithsonian , 60 Garden St., Cambridge, MA 02138, USAINAF—Osservatorio di Astrofisica e Scienza dello Spazio , via Gobetti 93/3, I-40129, Bologna, ItalySteward Observatory, University of Arizona , 933 N Cherry Ave, Tucson, AZ 85721, USAGemini Observatory , NSF’s NOIRLab, 670 N A’ohoku Place, Hilo, HI 96720, USANúcleo de Astronomía, Facultad de Ingeniera y Ciencias, Universidad Diego Portales , Av. Ejército 441, Santiago, 8320000, ChileLeiden Observatory, Leiden University , P.O. Box 9513, 2300 RA Leiden, The NetherlandsMax Planck Institut für Astronomie , Königstuhl 17, D-69117, Heidelberg, Germany ; schindler@strw.leidenuniv.nlJet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive, Pasadena, CA 91109, USALeiden Observatory, Leiden University , P.O. Box 9513, 2300 RA Leiden, The NetherlandsMax Planck Institut für Astronomie , Königstuhl 17, D-69117, Heidelberg, Germany ; schindler@strw.leidenuniv.nlWe present the z ≈ 6 type-1 quasar luminosity function (QLF), based on the Pan-STARRS1 (PS1) quasar survey. The PS1 sample includes 125 quasars at z ≈ 5.7–6.2, with −28 ≲ M _1450 ≲ −25. With the addition of 48 fainter quasars from the SHELLQs survey, we evaluate the z ≈ 6 QLF over −28 ≲ M _1450 ≲ −22. Adopting a double power law with an exponential evolution of the quasar density (Φ( z ) ∝ 10 ^k ^( ^z ^−6) ; k = −0.7), we use a maximum likelihood method to model our data. We find a break magnitude of ${M}^{* }=-{26.38}_{-0.60}^{+0.79}\,\mathrm{mag}$ , a faint-end slope of $\alpha =-{1.70}_{-0.19}^{+0.29}$ , and a steep bright-end slope of $\beta =-{3.84}_{-1.21}^{+0.63}$ . Based on our new QLF model, we determine the quasar comoving spatial density at z ≈ 6 to be $n({M}_{1450}\lt -26)={1.16}_{-0.12}^{+0.13}\,{\mathrm{cGpc}}^{-3}$ . In comparison with the literature, we find the quasar density to evolve with a constant value of k ≈ −0.7, from z ≈ 7 to z ≈ 4. Additionally, we derive an ionizing emissivity of ${\epsilon }_{912}(z=6)={7.23}_{-1.02}^{+1.65}\times {10}^{22}\,\mathrm{erg}\,{{\rm{s}}}^{-1}\,{\mathrm{Hz}}^{-1}\,{\mathrm{cMpc}}^{-3}$ , based on the QLF measurement. Given standard assumptions, and the recent measurement of the mean free path by Becker et al. at z ≈ 6, we calculate an H i photoionizing rate of Γ _H I ( z = 6) ≈ 6 × 10 ^−16 s ^−1 , strongly disfavoring a dominant role of quasars in hydrogen reionization.https://doi.org/10.3847/1538-4357/aca7caQuasarsSupermassive black holesReionizationEarly universeLuminosity function |
| spellingShingle | Jan-Torge Schindler Eduardo Bañados Thomas Connor Roberto Decarli Xiaohui Fan Emanuele Paolo Farina Chiara Mazzucchelli Riccardo Nanni Hans-Walter Rix Daniel Stern Bram P. Venemans Fabian Walter The Pan-STARRS1 z > 5.6 Quasar Survey. III. The z ≈ 6 Quasar Luminosity Function The Astrophysical Journal Quasars Supermassive black holes Reionization Early universe Luminosity function |
| title | The Pan-STARRS1 z > 5.6 Quasar Survey. III. The z ≈ 6 Quasar Luminosity Function |
| title_full | The Pan-STARRS1 z > 5.6 Quasar Survey. III. The z ≈ 6 Quasar Luminosity Function |
| title_fullStr | The Pan-STARRS1 z > 5.6 Quasar Survey. III. The z ≈ 6 Quasar Luminosity Function |
| title_full_unstemmed | The Pan-STARRS1 z > 5.6 Quasar Survey. III. The z ≈ 6 Quasar Luminosity Function |
| title_short | The Pan-STARRS1 z > 5.6 Quasar Survey. III. The z ≈ 6 Quasar Luminosity Function |
| title_sort | pan starrs1 z 5 6 quasar survey iii the z ≈ 6 quasar luminosity function |
| topic | Quasars Supermassive black holes Reionization Early universe Luminosity function |
| url | https://doi.org/10.3847/1538-4357/aca7ca |
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