GD-1 Stellar Stream and Cocoon in the DESI Early Data Release
We present ∼115 new spectroscopically identified members of the GD-1 tidal stream observed with the 5000-fiber Dark Energy Spectroscopic Instrument (DESI). We confirm the existence of a “cocoon,” which is a broad (FWHM ∼ 2 $\mathop{.}\limits^{\unicode{x000b0}}$ 932 ∼ 460 pc) and kinematically hot (...
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2025-01-01
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| author | M. Valluri P. Fagrelius S. E. Koposov T. S. Li Oleg Y. Gnedin E. F. Bell R. G. Carlberg A. P. Cooper J. Aguilar S. Ahlen C. Allende Prieto V. Belokurov L. Beraldo e Silva D. Brooks A. Byström T. Claybaugh K. Dawson A. Dey P. Doel J. E. Forero-Romero E. Gaztañaga S. Gontcho A Gontcho J. Han K. Honscheid T. Kisner A. Kremin A. Lambert M. Landriau L. Le Guillou M. E. Levi A. de la Macorra M. Manera P. Martini G. E. Medina A. Meisner R. Miquel J. Moustakas A. D. Myers J. Najita C. Poppett F. Prada M. Rezaie G. Rossi A. H. Riley E. Sanchez D. Schlegel M. Schubnell D. Sprayberry G. Tarlé G. Thomas B. A. Weaver R. H. Wechsler R. Zhou H. Zou |
| author_facet | M. Valluri P. Fagrelius S. E. Koposov T. S. Li Oleg Y. Gnedin E. F. Bell R. G. Carlberg A. P. Cooper J. Aguilar S. Ahlen C. Allende Prieto V. Belokurov L. Beraldo e Silva D. Brooks A. Byström T. Claybaugh K. Dawson A. Dey P. Doel J. E. Forero-Romero E. Gaztañaga S. Gontcho A Gontcho J. Han K. Honscheid T. Kisner A. Kremin A. Lambert M. Landriau L. Le Guillou M. E. Levi A. de la Macorra M. Manera P. Martini G. E. Medina A. Meisner R. Miquel J. Moustakas A. D. Myers J. Najita C. Poppett F. Prada M. Rezaie G. Rossi A. H. Riley E. Sanchez D. Schlegel M. Schubnell D. Sprayberry G. Tarlé G. Thomas B. A. Weaver R. H. Wechsler R. Zhou H. Zou |
| author_sort | M. Valluri |
| collection | DOAJ |
| description | We present ∼115 new spectroscopically identified members of the GD-1 tidal stream observed with the 5000-fiber Dark Energy Spectroscopic Instrument (DESI). We confirm the existence of a “cocoon,” which is a broad (FWHM ∼ 2 $\mathop{.}\limits^{\unicode{x000b0}}$ 932 ∼ 460 pc) and kinematically hot (velocity dispersion, σ ∼ 5–8 km s ^−1 ) component that surrounds a narrower (FWHM ∼ 0 $\mathop{.}\limits^{\unicode{x000b0}}$ 353 ∼ 55 pc) and colder [( σ = 3.09 ± 0.76 km s ^−1 )] thin stream component (based on a median per star velocity precision of 2.7 km s ^−1 ). The cocoon extends over at least a 30 ^∘ segment of the stream observed by DESI. The thin and cocoon components have similar mean values of [Fe/H]: −2.54 ± 0.04 dex and −2.47 ± 0.06 dex, suggestive of a common origin. The data are consistent with the following scenarios for the origin of the cocoon. The progenitor of the GD-1 stream was an accreted globular cluster (GC) and: (a) the cocoon was produced by pre-accretion tidal stripping of the GC while it was still inside its parent dwarf galaxy; (b) the cocoon comprises debris from the parent dwarf galaxy; (c) an initially thin GC tidal stream was heated by impacts from dark subhalos in the Milky Way; (d) an initially thin GC stream was heated by a massive Sagittarius dwarf galaxy; or a combination of some of these. Future DESI spectroscopy and detailed modeling may enable us to distinguish between these possible origins. |
| format | Article |
| id | doaj-art-5050bb919a184f9da8d433d1459ac7e4 |
| institution | Kabale University |
| issn | 1538-4357 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj-art-5050bb919a184f9da8d433d1459ac7e42025-02-05T15:00:16ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-0198017110.3847/1538-4357/ada690GD-1 Stellar Stream and Cocoon in the DESI Early Data ReleaseM. Valluri0https://orcid.org/0000-0002-6257-2341P. Fagrelius1S. E. Koposov2https://orcid.org/0000-0003-2644-135XT. S. Li3https://orcid.org/0000-0002-9110-6163Oleg Y. Gnedin4https://orcid.org/0000-0001-9852-9954E. F. Bell5https://orcid.org/0000-0002-5564-9873R. G. Carlberg6https://orcid.org/0000-0002-7667-0081A. P. Cooper7https://orcid.org/0000-0001-8274-158XJ. Aguilar8https://orcid.org/0000-0003-0822-452XS. Ahlen9https://orcid.org/0000-0001-6098-7247C. Allende Prieto10https://orcid.org/0000-0002-0084-572XV. Belokurov11https://orcid.org/0000-0002-0038-9584L. Beraldo e Silva12https://orcid.org/0000-0002-0740-1507D. Brooks13https://orcid.org/0000-0002-8458-5047A. Byström14https://orcid.org/0000-0002-5689-8791T. Claybaugh15K. Dawson16https://orcid.org/0000-0002-0553-3805A. Dey17https://orcid.org/0000-0002-4928-4003P. Doel18J. E. Forero-Romero19https://orcid.org/0000-0002-2890-3725E. Gaztañaga20https://orcid.org/0000-0001-9632-0815S. Gontcho A Gontcho21https://orcid.org/0000-0003-3142-233XJ. Han22https://orcid.org/0000-0002-6800-5778K. Honscheid23T. Kisner24https://orcid.org/0000-0003-3510-7134A. Kremin25https://orcid.org/0000-0001-6356-7424A. Lambert26M. Landriau27https://orcid.org/0000-0003-1838-8528L. Le Guillou28https://orcid.org/0000-0001-7178-8868M. E. Levi29https://orcid.org/0000-0003-1887-1018A. de la Macorra30https://orcid.org/0000-0002-1769-1640M. Manera31https://orcid.org/0000-0003-4962-8934P. Martini32https://orcid.org/0000-0002-0194-4017G. E. Medina33https://orcid.org/0000-0003-0105-9576A. Meisner34https://orcid.org/0000-0002-1125-7384R. Miquel35J. Moustakas36https://orcid.org/0000-0002-2733-4559A. D. Myers37J. Najita38https://orcid.org/0000-0002-5758-150XC. Poppett39F. Prada40https://orcid.org/0000-0001-7145-8674M. Rezaie41https://orcid.org/0000-0001-5589-7116G. Rossi42A. H. Riley43https://orcid.org/0000-0001-5805-5766E. Sanchez44https://orcid.org/0000-0002-9646-8198D. Schlegel45https://orcid.org/0000-0002-5042-5088M. Schubnell46D. Sprayberry47https://orcid.org/0000-0001-7583-6441G. Tarlé48https://orcid.org/0000-0003-1704-0781G. Thomas49https://orcid.org/0000-0002-2468-5521B. A. Weaver50R. H. Wechsler51https://orcid.org/0000-0003-2229-011XR. Zhou52https://orcid.org/0000-0001-5381-4372H. Zou53https://orcid.org/0000-0002-6684-3997Department of Astronomy, University of Michigan , Ann Arbor, MI 48109, USA ; mvalluri@umich.eduNSF NOIRLab , 950 N. Cherry Avenue, Tucson, AZ 85719, USAInstitute for Astronomy, University of Edinburgh , Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK; Institute of Astronomy, University of Cambridge , Madingley Road, Cambridge CB3 0HA, UKDepartment of Astronomy & Astrophysics, University of Toronto , Toronto, ON M5S 3H4, CanadaDepartment of Astronomy, University of Michigan , Ann Arbor, MI 48109, USA ; mvalluri@umich.eduDepartment of Astronomy, University of Michigan , Ann Arbor, MI 48109, USA ; mvalluri@umich.eduDepartment of Astronomy & Astrophysics, University of Toronto , Toronto, ON M5S 3H4, CanadaInstitute of Astronomy and Department of Physics, National Tsing Hua University , 101 Kuang-Fu Road Sec. 2, Hsinchu 30013, TaiwanLawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720, USAPhysics Dept., Boston University , 590 Commonwealth Avenue, Boston, MA 02215, USADepartamento de Astrofísica, Universidad de La Laguna (ULL) , E-38206, La Laguna, Tenerife, Spain; Instituto de Astrofísica de Canarias , C/ Vía Láctea, s/n, E-38205 La Laguna, Tenerife, SpainInstitute of Astronomy , Madingley Road, Cambridge CB3 0HA, UKSteward Observatory, University of Arizona , 933 N, Cherry Avenue, Tucson, AZ 85721, USADepartment of Physics & Astronomy, University College London , Gower Street, London, WC1E 6BT, UKInstitute for Astronomy, University of Edinburgh , Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UKLawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720, USADepartment of Physics and Astronomy, The University of Utah , 115 South 1400 East, Salt Lake City, UT 84112, USANSF NOIRLab , 950 N. Cherry Avenue, Tucson, AZ 85719, USADepartment of Physics & Astronomy, University College London , Gower Street, London, WC1E 6BT, UKDepartamento de Física, Universidad de los Andes , Cra. 1 No. 18A-10, Edificio Ip, CP 111711, Bogotá, ColombiaInstitut d’Estudis Espacials de Catalunya (IEEC) , 08034 Barcelona, Spain; Institute of Cosmology and Gravitation, University of Portsmouth , Dennis Sciama Building, Portsmouth, PO1 3FX, UK; Institute of Space Sciences , ICE-CSIC, Campus UAB, Carrer de Can Magrans s/n, 08913 Bellaterra, Barcelona, SpainLawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720, USACenter for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USACenter for Cosmology and AstroParticle Physics, The Ohio State University , 191 West Woodruff Avenue, Columbus, OH 43210, USA; Department of Physics, The Ohio State University , 191 West Woodruff Avenue, Columbus, OH 43210, USA; The Ohio State University , Columbus, 43210 OH, USALawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720, USALawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720, USALawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720, USALawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720, USASorbonne Université , CNRS/IN2P3, Laboratoire de Physique Nucléaire et de Hautes Energies (LPNHE), FR-75005 Paris, FranceLawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720, USAInstituto de Física, Universidad Nacional Autónoma de México , Cd. de México C.P. 04510, MéxicoDepartament de Física, Serra Húnter, Universitat Autònoma de Barcelona , 08193 Bellaterra (Barcelona), Spain; Institut de Física d’Altes Energies (IFAE) , The Barcelona Institute of Science and Technology, Campus UAB, 08193 Bellaterra Barcelona, SpainCenter for Cosmology and AstroParticle Physics, The Ohio State University , 191 West Woodruff Avenue, Columbus, OH 43210, USA; The Ohio State University , Columbus, 43210 OH, USA; Department of Astronomy, The Ohio State University , 4055 McPherson Laboratory, 140 W 18th Avenue, Columbus, OH 43210, USADepartment of Astronomy & Astrophysics, University of Toronto , Toronto, ON M5S 3H4, CanadaNSF NOIRLab , 950 N. Cherry Avenue, Tucson, AZ 85719, USAInstitut de Física d’Altes Energies (IFAE) , The Barcelona Institute of Science and Technology, Campus UAB, 08193 Bellaterra Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats , Passeig de Lluís Companys, 23, 08010 Barcelona, SpainDepartment of Physics and Astronomy, Siena College , 515 Loudon Road, Loudonville, NY 12211, USADepartment of Physics & Astronomy, University of Wyoming , 1000 E. University, Dept. 3905, Laramie, WY 82071, USANSF NOIRLab , 950 N. Cherry Avenue, Tucson, AZ 85719, USASpace Sciences Laboratory, University of California , Berkeley, 7 Gauss Way, Berkeley, CA 94720, USA; University of California , Berkeley, 110 Sproul Hall #5800 Berkeley, CA 94720, USAInstituto de Astrofísica de Andalucía (CSIC) , Glorieta de la Astronomía, s/n, E-18008 Granada, SpainDepartment of Physics, Kansas State University , 116 Cardwell Hall, Manhattan, KS 66506, USADepartment of Physics and Astronomy, Sejong University , Seoul, 143-747, Republic of KoreaInstitute for Computational Cosmology, Department of Physics, Durham University , South Road, Durham DH1 3LE, UKCIEMAT , Avenida Complutense 40, E-28040 Madrid, SpainLawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720, USADepartment of Physics, University of Michigan , Ann Arbor, MI 48109, USA; University of Michigan , Ann Arbor, MI 48109, USANSF NOIRLab , 950 N. Cherry Avenue, Tucson, AZ 85719, USAUniversity of Michigan , Ann Arbor, MI 48109, USAInstituto de Astrofísica de Canarias , C/ Vía Láctea, s/n, E-38205 La Laguna, Tenerife, SpainDepartamento de Astrofísica, Universidad de La Laguna (ULL), E-38206, La Laguna, Tenerife, SpainNSF NOIRLab , 950 N. Cherry Avenue, Tucson, AZ 85719, USAKavli Institute for Particle Astrophysics and Cosmology, Stanford University , Menlo Park, CA 94305, USA; Physics Department, Stanford University , Stanford, CA 93405, USA; SLAC National Accelerator Laboratory , Menlo Park, CA 94305, USALawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, CA 94720, USANational Astronomical Observatories , Chinese Academy of Sciences, A20 Datun Road, Chaoyang District, Beijing, 100012, People's Republic of ChinaWe present ∼115 new spectroscopically identified members of the GD-1 tidal stream observed with the 5000-fiber Dark Energy Spectroscopic Instrument (DESI). We confirm the existence of a “cocoon,” which is a broad (FWHM ∼ 2 $\mathop{.}\limits^{\unicode{x000b0}}$ 932 ∼ 460 pc) and kinematically hot (velocity dispersion, σ ∼ 5–8 km s ^−1 ) component that surrounds a narrower (FWHM ∼ 0 $\mathop{.}\limits^{\unicode{x000b0}}$ 353 ∼ 55 pc) and colder [( σ = 3.09 ± 0.76 km s ^−1 )] thin stream component (based on a median per star velocity precision of 2.7 km s ^−1 ). The cocoon extends over at least a 30 ^∘ segment of the stream observed by DESI. The thin and cocoon components have similar mean values of [Fe/H]: −2.54 ± 0.04 dex and −2.47 ± 0.06 dex, suggestive of a common origin. The data are consistent with the following scenarios for the origin of the cocoon. The progenitor of the GD-1 stream was an accreted globular cluster (GC) and: (a) the cocoon was produced by pre-accretion tidal stripping of the GC while it was still inside its parent dwarf galaxy; (b) the cocoon comprises debris from the parent dwarf galaxy; (c) an initially thin GC tidal stream was heated by impacts from dark subhalos in the Milky Way; (d) an initially thin GC stream was heated by a massive Sagittarius dwarf galaxy; or a combination of some of these. Future DESI spectroscopy and detailed modeling may enable us to distinguish between these possible origins.https://doi.org/10.3847/1538-4357/ada690Atomic spectroscopySpectroscopyMilky Way dark matter haloDark matterStellar streamsMilky Way dynamics |
| spellingShingle | M. Valluri P. Fagrelius S. E. Koposov T. S. Li Oleg Y. Gnedin E. F. Bell R. G. Carlberg A. P. Cooper J. Aguilar S. Ahlen C. Allende Prieto V. Belokurov L. Beraldo e Silva D. Brooks A. Byström T. Claybaugh K. Dawson A. Dey P. Doel J. E. Forero-Romero E. Gaztañaga S. Gontcho A Gontcho J. Han K. Honscheid T. Kisner A. Kremin A. Lambert M. Landriau L. Le Guillou M. E. Levi A. de la Macorra M. Manera P. Martini G. E. Medina A. Meisner R. Miquel J. Moustakas A. D. Myers J. Najita C. Poppett F. Prada M. Rezaie G. Rossi A. H. Riley E. Sanchez D. Schlegel M. Schubnell D. Sprayberry G. Tarlé G. Thomas B. A. Weaver R. H. Wechsler R. Zhou H. Zou GD-1 Stellar Stream and Cocoon in the DESI Early Data Release The Astrophysical Journal Atomic spectroscopy Spectroscopy Milky Way dark matter halo Dark matter Stellar streams Milky Way dynamics |
| title | GD-1 Stellar Stream and Cocoon in the DESI Early Data Release |
| title_full | GD-1 Stellar Stream and Cocoon in the DESI Early Data Release |
| title_fullStr | GD-1 Stellar Stream and Cocoon in the DESI Early Data Release |
| title_full_unstemmed | GD-1 Stellar Stream and Cocoon in the DESI Early Data Release |
| title_short | GD-1 Stellar Stream and Cocoon in the DESI Early Data Release |
| title_sort | gd 1 stellar stream and cocoon in the desi early data release |
| topic | Atomic spectroscopy Spectroscopy Milky Way dark matter halo Dark matter Stellar streams Milky Way dynamics |
| url | https://doi.org/10.3847/1538-4357/ada690 |
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