Evidence of First Stars-enriched Gas in High-redshift Absorbers
The first stars were born from chemically pristine gas. They were likely massive, and thus they rapidly exploded as supernovae, enriching the surrounding gas with the first heavy elements. In the Local Group, the chemical signatures of the first stellar population were identified among low-mass, lon...
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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 |
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| Online Access: | https://doi.org/10.3847/1538-4357/acc39f |
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| author | Andrea Saccardi Stefania Salvadori Valentina D’Odorico Guido Cupani Michele Fumagalli Trystyn A. M. Berg George D. Becker Sara Ellison Sebastian Lopez |
| author_facet | Andrea Saccardi Stefania Salvadori Valentina D’Odorico Guido Cupani Michele Fumagalli Trystyn A. M. Berg George D. Becker Sara Ellison Sebastian Lopez |
| author_sort | Andrea Saccardi |
| collection | DOAJ |
| description | The first stars were born from chemically pristine gas. They were likely massive, and thus they rapidly exploded as supernovae, enriching the surrounding gas with the first heavy elements. In the Local Group, the chemical signatures of the first stellar population were identified among low-mass, long-lived, very metal-poor ([Fe/H] < −2) stars, characterized by high abundances of carbon over iron ([C/Fe] > +0.7): the so-called carbon-enhanced metal-poor stars. Conversely, a similar carbon excess caused by first-star pollution was not found in dense neutral gas traced by absorption systems at different cosmic time. Here we present the detection of 14 very metal-poor, optically thick absorbers at redshift z ∼ 3–4. Among these, 3 are carbon-enhanced and reveal an overabundance with respect to Fe of all the analyzed chemical elements (O, Mg, Al, and Si). Their relative abundances show a distribution with respect to [Fe/H] that is in very good agreement with those observed in nearby very metal-poor stars. All the tests we performed support the idea that these C-rich absorbers preserve the chemical yields of the first stars. Our new findings suggest that the first-star signatures can survive in optically thick but relatively diffuse absorbers, which are not sufficiently dense to sustain star formation and hence are not dominated by the chemical products of normal stars. |
| first_indexed | 2024-03-12T03:25:18Z |
| format | Article |
| id | doaj.art-b24f6054b7c743f798cb3e60b970b056 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T03:25:18Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
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| series | The Astrophysical Journal |
| spelling | doaj.art-b24f6054b7c743f798cb3e60b970b0562023-09-03T13:39:38ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0194813510.3847/1538-4357/acc39fEvidence of First Stars-enriched Gas in High-redshift AbsorbersAndrea Saccardi0https://orcid.org/0000-0002-6950-4587Stefania Salvadori1https://orcid.org/0000-0001-7298-2478Valentina D’Odorico2https://orcid.org/0000-0003-3693-3091Guido Cupani3https://orcid.org/0000-0002-6830-9093Michele Fumagalli4https://orcid.org/0000-0001-6676-3842Trystyn A. M. Berg5https://orcid.org/0000-0002-2606-5078George D. Becker6https://orcid.org/0000-0003-2344-263XSara Ellison7https://orcid.org/0000-0002-1768-1899Sebastian Lopez8https://orcid.org/0000-0003-0389-0902GEPI, Observatoire de Paris, Université PSL , CNRS, 5 Place Jules Janssen, F-92190 Meudon, France ; andrea.saccardi@obspm.fr; Dipartimento di Fisica e Astronomia, Università degli Studi di Firenze , Via G. Sansone 1, I-50019 Sesto Fiorentino, ItalyDipartimento di Fisica e Astronomia, Università degli Studi di Firenze , Via G. Sansone 1, I-50019 Sesto Fiorentino, Italy; INAF—Osservatorio Astrofisico di Arcetri , Largo E. Fermi 5, I-50125 Firenze, ItalyScuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy; INAF—Osservatorio Astronomico di Trieste , via G.B. Tiepolo, 11 I-34143 Trieste, Italy; IFPU—Institute for Fundamental Physics of the Universe , Via Beirut 2, I-34014 Trieste, ItalyINAF—Osservatorio Astronomico di Trieste , via G.B. Tiepolo, 11 I-34143 Trieste, Italy; IFPU—Institute for Fundamental Physics of the Universe , Via Beirut 2, I-34014 Trieste, ItalyINAF—Osservatorio Astronomico di Trieste , via G.B. Tiepolo, 11 I-34143 Trieste, Italy; Dipartimento di Fisica G. Occhialini, Università degli Studi di Milano Bicocca , Piazza della Scienza 3, I-20126 Milano, ItalyDipartimento di Fisica G. Occhialini, Università degli Studi di Milano Bicocca , Piazza della Scienza 3, I-20126 Milano, ItalyDepartment of Physics & Astronomy, University of California , Riverside, CA 92521, USADepartment of Physics & Astronomy, University of Victoria , Finnerty Road, Victoria, BC V8P 1A1, CanadaDepartamento de Astronomía, Universidad de Chile , Casilla 36-D, Santiago, ChileThe first stars were born from chemically pristine gas. They were likely massive, and thus they rapidly exploded as supernovae, enriching the surrounding gas with the first heavy elements. In the Local Group, the chemical signatures of the first stellar population were identified among low-mass, long-lived, very metal-poor ([Fe/H] < −2) stars, characterized by high abundances of carbon over iron ([C/Fe] > +0.7): the so-called carbon-enhanced metal-poor stars. Conversely, a similar carbon excess caused by first-star pollution was not found in dense neutral gas traced by absorption systems at different cosmic time. Here we present the detection of 14 very metal-poor, optically thick absorbers at redshift z ∼ 3–4. Among these, 3 are carbon-enhanced and reveal an overabundance with respect to Fe of all the analyzed chemical elements (O, Mg, Al, and Si). Their relative abundances show a distribution with respect to [Fe/H] that is in very good agreement with those observed in nearby very metal-poor stars. All the tests we performed support the idea that these C-rich absorbers preserve the chemical yields of the first stars. Our new findings suggest that the first-star signatures can survive in optically thick but relatively diffuse absorbers, which are not sufficiently dense to sustain star formation and hence are not dominated by the chemical products of normal stars.https://doi.org/10.3847/1538-4357/acc39fChemical abundancesQuasar absorption line spectroscopyMetallicity |
| spellingShingle | Andrea Saccardi Stefania Salvadori Valentina D’Odorico Guido Cupani Michele Fumagalli Trystyn A. M. Berg George D. Becker Sara Ellison Sebastian Lopez Evidence of First Stars-enriched Gas in High-redshift Absorbers The Astrophysical Journal Chemical abundances Quasar absorption line spectroscopy Metallicity |
| title | Evidence of First Stars-enriched Gas in High-redshift Absorbers |
| title_full | Evidence of First Stars-enriched Gas in High-redshift Absorbers |
| title_fullStr | Evidence of First Stars-enriched Gas in High-redshift Absorbers |
| title_full_unstemmed | Evidence of First Stars-enriched Gas in High-redshift Absorbers |
| title_short | Evidence of First Stars-enriched Gas in High-redshift Absorbers |
| title_sort | evidence of first stars enriched gas in high redshift absorbers |
| topic | Chemical abundances Quasar absorption line spectroscopy Metallicity |
| url | https://doi.org/10.3847/1538-4357/acc39f |
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