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DESI DR2 Galaxy luminosity functions

Moore, Samuel G [Institute for Computational Cosmology, Department of Physics, Durham University , South Road, Durham DH1 3LE ,] (ORCID:0000000348214246)·Cole, Shaun [Institute for Computational Cosmology, Department of Physics, Durham University , South Road, Durham DH1 3LE ,] (ORCID:0000000259547903)·Wilson, Michael [Institute for Computational Cosmology, Department of Physics, Durham University , South Road, Durham DH1 3LE ,; Department of Astrophysical Sciences, Princeton University , 4 Ivy Lane, Princeton, NJ 08544 ,]·Norberg, Peder [Institute for Computational Cosmology, Department of Physics, Durham University , South Road, Durham DH1 3LE ,; Centre for Extragalactic Astronomy, Department of Physics, Durham University , South Road, Durham DH1 3LE ,]·Moustakas, John [Department of Physics and Astronomy, Siena College , 515 Loudon Road, Loudonville, NY 12211 ,]·Aguilar, J [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,]·Ahlen, S [Department of Physics, Boston University , 590 Commonwealth Avenue, Boston, MA 02215]·Anand, A [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,]·Bianchi, D [Dipartimento di Fisica ‘Aldo Pontremoli’, Università degli Studi di Milano , Via Celoria 16, I-20133 Milano ,; INAF-Osservatorio Astronomico di Brera , Via Brera 28, 20122 Milano ,]·Brooks, D [Department of Physics & Astronomy, University College London , Gower Street, London, WC1E 6BT ,]·Castander, F J [Institut d’Estudis Espacials de Catalunya (IEEC) , c/ Esteve Terradas 1, Edifici RDIT, Campus PMT-UPC, E-08860 Castelldefels ,; Institute of Space Sciences , ICE-CSIC, Campus UAB, Carrer de Can Magrans s/n, E-08913 Bellaterra, Barcelona ,] (ORCID:0000000173164573)·Claybaugh, T [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,]·Cuceu, A [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,]·de la Macorra, A [Instituto de Física, Universidad Nacional Autónoma de México, Circuito de la Investigación Científica, Ciudad Universitaria , Cd. de México C. P. 04510 ,]·Dey, Arjun [NSF NOIRLab , 950 N. Cherry Ave., Tucson, AZ 85719 ,]·Dey, Biprateep [Department of Astronomy & Astrophysics, University of Toronto , Toronto, ON M5S 3H4 ,; Department of Physics & Astronomy and Pittsburgh Particle Physics, Astrophysics, and Cosmology Center (PITT PACC), University of Pittsburgh , 3941 O’Hara Street, Pittsburgh, PA 15260 ,]·Ferraro, S [Department of Physics and Astronomy, Siena College , 515 Loudon Road, Loudonville, NY 12211 ,; University of California , Berkeley, 110 Sproul Hall #5800 Berkeley, CA 94720 ,]·Font-Ribera, A [Institut de Física dâ Altes Energies (IFAE), The Barcelona Institute of Science and Technology , Edifici Cn, Campus UAB, E-08193, Bellaterra (Barcelona) ,] (ORCID:0000000230337312)·Forero-Romero, J E [Departamento de Física, Universidad de los Andes , Cra. 1 No. 18A-10, Edificio Ip, CP 111711, Bogotá ,; Observatorio Astronómico, Universidad de los Andes , Cra. 1 No. 18A-10, Edificio H, CP 111711 Bogotá ,] (ORCID:0000000228903725)·Gaztanaga, E [Institut d’Estudis Espacials de Catalunya (IEEC) , c/ Esteve Terradas 1, Edifici RDIT, Campus PMT-UPC, E-08860 Castelldefels ,; Institute of Space Sciences , ICE-CSIC, Campus UAB, Carrer de Can Magrans s/n, E-08913 Bellaterra, Barcelona ,; Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building , Portsmouth, PO1 3FX ,] (ORCID:0000000196320815)·Gontcho, S Gontcho A [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,; University of Virginia, Department of Astronomy , Charlottesville, VA 22904 ,]·Gutierrez, G [Fermi National Accelerator Laboratory , PO Box 500, Batavia, IL 60510 ,]·Herrera-Alcantar, H K [Institut d’Astrophysique de Paris. 98 bis boulevard Arago . F-75014 Paris ,; IRFU, CEA, Université Paris-Saclay , F-91191 Gif-sur-Yvette ,]·Honscheid, K [Center for Cosmology and AstroParticle Physics, The Ohio State University , 191 West Woodruff Avenue, Columbus, OH 43210 ,; Department of Physics, The Ohio State University , 191 West Woodruff Avenue, Columbus, OH 43210 ,; The Ohio State University , Columbus, 43210 OH ,]·Ishak, M [Department of Physics, The University of Texas at Dallas , 800 W. Campbell Rd., Richardson, TX 75080 ,]·Joyce, R [NSF NOIRLab , 950 N. Cherry Ave., Tucson, AZ 85719 ,]·Juneau, S [NSF NOIRLab , 950 N. Cherry Ave., Tucson, AZ 85719 ,] (ORCID:0000000200002394)·Kehoe, R [Department of Physics, Southern Methodist University , 3215 Daniel Avenue, Dallas, TX 75275 ,]·Kisner, T [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,]·Koposov, S E [Institute for Astronomy, University of Edinburgh, Royal Observatory , Blackford Hill, Edinburgh EH9 3HJ ,; Institute of Astronomy, University of Cambridge , Madingley Road, Cambridge CB3 0HA ,] (ORCID:000000032644135X)·Kremin, A [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,]·Lahav, O [Department of Physics & Astronomy, University College London , Gower Street, London, WC1E 6BT ,]·Lamman, C [The Ohio State University , Columbus, 43210 OH ,] (ORCID:0000000267319329)·Landriau, M [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,]·Le Guillou, L [Sorbonne Université, CNRS/IN2P3, Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE) , F-75005 Paris ,]·Levi, M E [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,]·Lucey, J R [Centre for Extragalactic Astronomy, Department of Physics, Durham University , South Road, Durham DH1 3LE ,] (ORCID:000000029748961X)·Manera, M [Institut de Física dâ Altes Energies (IFAE), The Barcelona Institute of Science and Technology , Edifici Cn, Campus UAB, E-08193, Bellaterra (Barcelona) ,; Departament de Física, Serra Húnter, Universitat Autònoma de Barcelona , E-08193 Bellaterra (Barcelona) ,]·Meisner, A [NSF NOIRLab , 950 N. Cherry Ave., Tucson, AZ 85719 ,]·Miquel, R [Institut de Física dâ Altes Energies (IFAE), The Barcelona Institute of Science and Technology , Edifici Cn, Campus UAB, E-08193, Bellaterra (Barcelona) ,; Institució Catalana de Recerca i Estudis Avançats, Passeig de Lluís Companys , 23, E-08010 Barcelona ,]·Nadathur, S [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building , Portsmouth, PO1 3FX ,] (ORCID:0000000190703102)·Percival, W J [Department of Physics and Astronomy, University of Waterloo , 200 University Ave W, Waterloo, ON N2L 3G1 ,; Perimeter Institute for Theoretical Physics , 31 Caroline St. North, Waterloo, ON N2L 2Y5 ,; Waterloo Centre for Astrophysics, University of Waterloo , 200 University Ave W, Waterloo, ON N2L 3G1 ,] (ORCID:0000000206445727)·Poppett, C [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,; University of California , Berkeley, 110 Sproul Hall #5800 Berkeley, CA 94720 ,; Space Sciences Laboratory, University of California , Berkeley, 7 Gauss Way, Berkeley, CA 94720 ,]·Prada, F [Instituto de Astrofísica de Andalucía (CSIC), Glorieta de la Astronomía , s/n, E-18008 Granada ,]·Ross, A J [Center for Cosmology and AstroParticle Physics, The Ohio State University , 191 West Woodruff Avenue, Columbus, OH 43210 ,; The Ohio State University , Columbus, 43210 OH ,; Department of Astronomy, The Ohio State University , 4055 McPherson Laboratory, 140 W 18th Avenue, Columbus, OH 43210 ,]·Rossi, G [Department of Physics and Astronomy, Sejong University , 209 Neungdong-ro, Gwangjin-gu, Seoul 05006 ,]·Sanchez, E [CIEMAT , Avenida Complutense 40, E-28040 Madrid ,] (ORCID:0000000296468198)·Schlegel, D [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,]·Schubnell, M [Department of Physics, University of Michigan , 450 Church Street, Ann Arbor, MI 48109 ,; University of Michigan , 500 S. State Street, Ann Arbor, MI 48109 ,]·Seo, H [Department of Physics & Astronomy, Ohio University , 139 University Terrace, Athens, OH 45701 ,] (ORCID:0000000265883508)·Silber, J [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,]·Sprayberry, D [NSF NOIRLab , 950 N. Cherry Ave., Tucson, AZ 85719 ,]·Tarlé, G [University of Michigan , 500 S. State Street, Ann Arbor, MI 48109 ,]·Weaver, B A [NSF NOIRLab , 950 N. Cherry Ave., Tucson, AZ 85719 ,]·Wechsler, R H [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University , Menlo Park, CA 94305 ,; Physics Department, Stanford University , Stanford, CA 93405 ,; SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, CA 94025 ,]·Zhou, R [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,] (ORCID:0000000153814372)·Zou, H [National Astronomical Observatories, Chinese Academy of Sciences , A20 Datun Road, Chaoyang District, Beijing, 100101 ,]

Abstract

We present galaxy luminosity functions (LFs) for the Dark Energy Spectroscopic Instrument (DESI) DR2 Bright Galaxy Survey (BGS) in the g, r, z, and $w1$ bands over $0.002\lt z\lt 0.6$. Our analysis uses updated k-corrections and evolutionary corrections, including new polynomial kcorrection fits derived from BGS Year 1 data that supersede earlier GAMA-based prescriptions. Exploiting the statistical power of DESI, we measure LFs to very faint magnitudes, reaching $^{0.1}M_r-5\log h\sim -10$. Independent measurements from the North and South survey regions show excellent agreement around the LF knee, but the very small statistical uncertainties reveal that simple analytic forms fail to capture the full LF shape. The bright end departs from a pure exponential decline, while the faint end exhibits complex, non-powerlaw behaviour, including a pronounced upturn at $^{0.1}M_r-5\log h\gtrsim -15$, which is stronger for red galaxies than for blue. We show that our LFs are largely complete for galaxies with surface brightness $\mu _{50}\lt 25$, and that an apparent steepening fainter than $-13$ is driven primarily by local overdensity and fragmentation of large galaxies. A systematic North–South offset at the brightest magnitudes is traced to red galaxies and may reflect shallower North photometry underestimating extended earlytype profiles, although this remains inconclusive. We therefore also provide LFs based on model Petrosian magnitudes. Redshift splitting reveals small but significant residuals, indicating limitations of a simple global evolutionary model. Using the redshift limits of J. Loveday et al. (2012), we find excellent agreement with GAMA, with substantially reduced statistical errors. These measurements provide a precise reference for studies of environmental and population-dependent LFs and for testing galaxy formation models.

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BibTeXRIS

Moore, Samuel G [Institute for Computational Cosmology, Department of Physics, Durham University , South Road, Durham DH1 3LE ,] (ORCID:0000000348214246), Cole, Shaun [Institute for Computational Cosmology, Department of Physics, Durham University , South Road, Durham DH1 3LE ,] (ORCID:0000000259547903), Wilson, Michael [Institute for Computational Cosmology, Department of Physics, Durham University , South Road, Durham DH1 3LE ,; Department of Astrophysical Sciences, Princeton University , 4 Ivy Lane, Princeton, NJ 08544 ,], Norberg, Peder [Institute for Computational Cosmology, Department of Physics, Durham University , South Road, Durham DH1 3LE ,; Centre for Extragalactic Astronomy, Department of Physics, Durham University , South Road, Durham DH1 3LE ,], Moustakas, John [Department of Physics and Astronomy, Siena College , 515 Loudon Road, Loudonville, NY 12211 ,], Aguilar, J [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], Ahlen, S [Department of Physics, Boston University , 590 Commonwealth Avenue, Boston, MA 02215], Anand, A [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], Bianchi, D [Dipartimento di Fisica ‘Aldo Pontremoli’, Università degli Studi di Milano , Via Celoria 16, I-20133 Milano ,; INAF-Osservatorio Astronomico di Brera , Via Brera 28, 20122 Milano ,], Brooks, D [Department of Physics & Astronomy, University College London , Gower Street, London, WC1E 6BT ,], Castander, F J [Institut d’Estudis Espacials de Catalunya (IEEC) , c/ Esteve Terradas 1, Edifici RDIT, Campus PMT-UPC, E-08860 Castelldefels ,; Institute of Space Sciences , ICE-CSIC, Campus UAB, Carrer de Can Magrans s/n, E-08913 Bellaterra, Barcelona ,] (ORCID:0000000173164573), Claybaugh, T [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], Cuceu, A [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], de la Macorra, A [Instituto de Física, Universidad Nacional Autónoma de México, Circuito de la Investigación Científica, Ciudad Universitaria , Cd. de México C. P. 04510 ,], Dey, Arjun [NSF NOIRLab , 950 N. Cherry Ave., Tucson, AZ 85719 ,], Dey, Biprateep [Department of Astronomy & Astrophysics, University of Toronto , Toronto, ON M5S 3H4 ,; Department of Physics & Astronomy and Pittsburgh Particle Physics, Astrophysics, and Cosmology Center (PITT PACC), University of Pittsburgh , 3941 O’Hara Street, Pittsburgh, PA 15260 ,], Ferraro, S [Department of Physics and Astronomy, Siena College , 515 Loudon Road, Loudonville, NY 12211 ,; University of California , Berkeley, 110 Sproul Hall #5800 Berkeley, CA 94720 ,], Font-Ribera, A [Institut de Física dâ Altes Energies (IFAE), The Barcelona Institute of Science and Technology , Edifici Cn, Campus UAB, E-08193, Bellaterra (Barcelona) ,] (ORCID:0000000230337312), Forero-Romero, J E [Departamento de Física, Universidad de los Andes , Cra. 1 No. 18A-10, Edificio Ip, CP 111711, Bogotá ,; Observatorio Astronómico, Universidad de los Andes , Cra. 1 No. 18A-10, Edificio H, CP 111711 Bogotá ,] (ORCID:0000000228903725), Gaztanaga, E [Institut d’Estudis Espacials de Catalunya (IEEC) , c/ Esteve Terradas 1, Edifici RDIT, Campus PMT-UPC, E-08860 Castelldefels ,; Institute of Space Sciences , ICE-CSIC, Campus UAB, Carrer de Can Magrans s/n, E-08913 Bellaterra, Barcelona ,; Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building , Portsmouth, PO1 3FX ,] (ORCID:0000000196320815), Gontcho, S Gontcho A [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,; University of Virginia, Department of Astronomy , Charlottesville, VA 22904 ,], Gutierrez, G [Fermi National Accelerator Laboratory , PO Box 500, Batavia, IL 60510 ,], Herrera-Alcantar, H K [Institut d’Astrophysique de Paris. 98 bis boulevard Arago . F-75014 Paris ,; IRFU, CEA, Université Paris-Saclay , F-91191 Gif-sur-Yvette ,], Honscheid, K [Center for Cosmology and AstroParticle Physics, The Ohio State University , 191 West Woodruff Avenue, Columbus, OH 43210 ,; Department of Physics, The Ohio State University , 191 West Woodruff Avenue, Columbus, OH 43210 ,; The Ohio State University , Columbus, 43210 OH ,], Ishak, M [Department of Physics, The University of Texas at Dallas , 800 W. Campbell Rd., Richardson, TX 75080 ,], Joyce, R [NSF NOIRLab , 950 N. Cherry Ave., Tucson, AZ 85719 ,], Juneau, S [NSF NOIRLab , 950 N. Cherry Ave., Tucson, AZ 85719 ,] (ORCID:0000000200002394), Kehoe, R [Department of Physics, Southern Methodist University , 3215 Daniel Avenue, Dallas, TX 75275 ,], Kisner, T [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], Koposov, S E [Institute for Astronomy, University of Edinburgh, Royal Observatory , Blackford Hill, Edinburgh EH9 3HJ ,; Institute of Astronomy, University of Cambridge , Madingley Road, Cambridge CB3 0HA ,] (ORCID:000000032644135X), Kremin, A [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], Lahav, O [Department of Physics & Astronomy, University College London , Gower Street, London, WC1E 6BT ,], Lamman, C [The Ohio State University , Columbus, 43210 OH ,] (ORCID:0000000267319329), Landriau, M [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], Le Guillou, L [Sorbonne Université, CNRS/IN2P3, Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE) , F-75005 Paris ,], Levi, M E [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], Lucey, J R [Centre for Extragalactic Astronomy, Department of Physics, Durham University , South Road, Durham DH1 3LE ,] (ORCID:000000029748961X), Manera, M [Institut de Física dâ Altes Energies (IFAE), The Barcelona Institute of Science and Technology , Edifici Cn, Campus UAB, E-08193, Bellaterra (Barcelona) ,; Departament de Física, Serra Húnter, Universitat Autònoma de Barcelona , E-08193 Bellaterra (Barcelona) ,], Meisner, A [NSF NOIRLab , 950 N. Cherry Ave., Tucson, AZ 85719 ,], Miquel, R [Institut de Física dâ Altes Energies (IFAE), The Barcelona Institute of Science and Technology , Edifici Cn, Campus UAB, E-08193, Bellaterra (Barcelona) ,; Institució Catalana de Recerca i Estudis Avançats, Passeig de Lluís Companys , 23, E-08010 Barcelona ,], Nadathur, S [Institute of Cosmology and Gravitation, University of Portsmouth, Dennis Sciama Building , Portsmouth, PO1 3FX ,] (ORCID:0000000190703102), Percival, W J [Department of Physics and Astronomy, University of Waterloo , 200 University Ave W, Waterloo, ON N2L 3G1 ,; Perimeter Institute for Theoretical Physics , 31 Caroline St. North, Waterloo, ON N2L 2Y5 ,; Waterloo Centre for Astrophysics, University of Waterloo , 200 University Ave W, Waterloo, ON N2L 3G1 ,] (ORCID:0000000206445727), Poppett, C [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,; University of California , Berkeley, 110 Sproul Hall #5800 Berkeley, CA 94720 ,; Space Sciences Laboratory, University of California , Berkeley, 7 Gauss Way, Berkeley, CA 94720 ,], Prada, F [Instituto de Astrofísica de Andalucía (CSIC), Glorieta de la Astronomía , s/n, E-18008 Granada ,], Ross, A J [Center for Cosmology and AstroParticle Physics, The Ohio State University , 191 West Woodruff Avenue, Columbus, OH 43210 ,; The Ohio State University , Columbus, 43210 OH ,; Department of Astronomy, The Ohio State University , 4055 McPherson Laboratory, 140 W 18th Avenue, Columbus, OH 43210 ,], Rossi, G [Department of Physics and Astronomy, Sejong University , 209 Neungdong-ro, Gwangjin-gu, Seoul 05006 ,], Sanchez, E [CIEMAT , Avenida Complutense 40, E-28040 Madrid ,] (ORCID:0000000296468198), Schlegel, D [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], Schubnell, M [Department of Physics, University of Michigan , 450 Church Street, Ann Arbor, MI 48109 ,; University of Michigan , 500 S. State Street, Ann Arbor, MI 48109 ,], Seo, H [Department of Physics & Astronomy, Ohio University , 139 University Terrace, Athens, OH 45701 ,] (ORCID:0000000265883508), Silber, J [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,], Sprayberry, D [NSF NOIRLab , 950 N. Cherry Ave., Tucson, AZ 85719 ,], Tarlé, G [University of Michigan , 500 S. State Street, Ann Arbor, MI 48109 ,], Weaver, B A [NSF NOIRLab , 950 N. Cherry Ave., Tucson, AZ 85719 ,], Wechsler, R H [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University , Menlo Park, CA 94305 ,; Physics Department, Stanford University , Stanford, CA 93405 ,; SLAC National Accelerator Laboratory , 2575 Sand Hill Road, Menlo Park, CA 94025 ,], Zhou, R [Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720 ,] (ORCID:0000000153814372), Zou, H [National Astronomical Observatories, Chinese Academy of Sciences , A20 Datun Road, Chaoyang District, Beijing, 100101 ,]. 2026-05-08. DESI DR2 Galaxy luminosity functions. https://doi.org/10.1093/mnras%2Fstag866

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