Spectroscopic confirmation of an ultramassive and compact galaxy at Z = 3.35: A detailed look at an early progenitor of local giant ellipticals
We present the first spectroscopic confirmation of an ultramassive galaxy at redshift z > 3 using data from Keck- NIRSPEC, VLT-X-shooter, and GTC-Osiris. We detect strong [O III] and Lya emission, and weak [O II], C IV, and He II, placing C1-23152 at a spectroscopic redshift of zspec = 3.351....
| Main Authors: | , , , , , , , , , , , , |
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| Format: | Journal Article |
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Institute of Physics Publishing
2015
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| Online Access: | http://hdl.handle.net/20.500.11937/73888 |
| _version_ | 1848763124296974336 |
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| author | Marsan, Z. Marchesini, D. Brammer, G. Stefanon, M. Muzzin, A. Fernández-Soto, A. Geier, S. Hainline, K. Intema, Hubertus Karim, A. Labbé, I. Toft, S. Dokkum, P. |
| author_facet | Marsan, Z. Marchesini, D. Brammer, G. Stefanon, M. Muzzin, A. Fernández-Soto, A. Geier, S. Hainline, K. Intema, Hubertus Karim, A. Labbé, I. Toft, S. Dokkum, P. |
| author_sort | Marsan, Z. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | We present the first spectroscopic confirmation of an ultramassive galaxy at redshift z > 3 using data from Keck- NIRSPEC, VLT-X-shooter, and GTC-Osiris. We detect strong [O III] and Lya emission, and weak [O II], C IV, and He II, placing C1-23152 at a spectroscopic redshift of zspec = 3.351. The modeling of the emission-line-corrected spectral energy distribution (SED) results in a best-fit stellar mass of M* = 3.1-0.7+0.6 × 1011 M?, a star formation rate of <7 M?yr-1, and negligible dust extinction. The stars appear to have formed in a short intense burst ~300-500 Myr prior to the observation epoch, setting the formation redshift of this galaxy at z ~ 4.1. From the analysis of the line ratios and widths and the observed flux at 24 µm, we confirm the presence of a luminous hidden active galactic nucleus (AGN), with bolometric luminosity of ~1046 erg s-1. Potential contamination of the observed SED from the AGN continuum is constrained, placing a lower limit on the stellar mass of 2 × 1011 M?. HST/WFC3 H160 and ACS I814 images are modeled, resulting in an effective radius of re ~ 1 kpc in the H160 band and a -Sti-errsic index n ~ 4.4. This object may be a prototype of the progenitors of local most massive elliptical galaxies in the first 2 Gyr of cosmic history, having formed most of its stars at z > 4 in a highly dissipative, intense, and short burst of star formation. C1-23152 is completing its transition to a post-starburst phase while hosting a powerful AGN, potentially responsible for the quenching of the star formation activity. |
| first_indexed | 2025-11-14T10:58:28Z |
| format | Journal Article |
| id | curtin-20.500.11937-73888 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T10:58:28Z |
| publishDate | 2015 |
| publisher | Institute of Physics Publishing |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-738882019-06-25T07:46:46Z Spectroscopic confirmation of an ultramassive and compact galaxy at Z = 3.35: A detailed look at an early progenitor of local giant ellipticals Marsan, Z. Marchesini, D. Brammer, G. Stefanon, M. Muzzin, A. Fernández-Soto, A. Geier, S. Hainline, K. Intema, Hubertus Karim, A. Labbé, I. Toft, S. Dokkum, P. We present the first spectroscopic confirmation of an ultramassive galaxy at redshift z > 3 using data from Keck- NIRSPEC, VLT-X-shooter, and GTC-Osiris. We detect strong [O III] and Lya emission, and weak [O II], C IV, and He II, placing C1-23152 at a spectroscopic redshift of zspec = 3.351. The modeling of the emission-line-corrected spectral energy distribution (SED) results in a best-fit stellar mass of M* = 3.1-0.7+0.6 × 1011 M?, a star formation rate of <7 M?yr-1, and negligible dust extinction. The stars appear to have formed in a short intense burst ~300-500 Myr prior to the observation epoch, setting the formation redshift of this galaxy at z ~ 4.1. From the analysis of the line ratios and widths and the observed flux at 24 µm, we confirm the presence of a luminous hidden active galactic nucleus (AGN), with bolometric luminosity of ~1046 erg s-1. Potential contamination of the observed SED from the AGN continuum is constrained, placing a lower limit on the stellar mass of 2 × 1011 M?. HST/WFC3 H160 and ACS I814 images are modeled, resulting in an effective radius of re ~ 1 kpc in the H160 band and a -Sti-errsic index n ~ 4.4. This object may be a prototype of the progenitors of local most massive elliptical galaxies in the first 2 Gyr of cosmic history, having formed most of its stars at z > 4 in a highly dissipative, intense, and short burst of star formation. C1-23152 is completing its transition to a post-starburst phase while hosting a powerful AGN, potentially responsible for the quenching of the star formation activity. 2015 Journal Article http://hdl.handle.net/20.500.11937/73888 10.1088/0004-637X/801/2/133 Institute of Physics Publishing restricted |
| spellingShingle | Marsan, Z. Marchesini, D. Brammer, G. Stefanon, M. Muzzin, A. Fernández-Soto, A. Geier, S. Hainline, K. Intema, Hubertus Karim, A. Labbé, I. Toft, S. Dokkum, P. Spectroscopic confirmation of an ultramassive and compact galaxy at Z = 3.35: A detailed look at an early progenitor of local giant ellipticals |
| title | Spectroscopic confirmation of an ultramassive and compact galaxy at Z = 3.35: A detailed look at an early progenitor of local giant ellipticals |
| title_full | Spectroscopic confirmation of an ultramassive and compact galaxy at Z = 3.35: A detailed look at an early progenitor of local giant ellipticals |
| title_fullStr | Spectroscopic confirmation of an ultramassive and compact galaxy at Z = 3.35: A detailed look at an early progenitor of local giant ellipticals |
| title_full_unstemmed | Spectroscopic confirmation of an ultramassive and compact galaxy at Z = 3.35: A detailed look at an early progenitor of local giant ellipticals |
| title_short | Spectroscopic confirmation of an ultramassive and compact galaxy at Z = 3.35: A detailed look at an early progenitor of local giant ellipticals |
| title_sort | spectroscopic confirmation of an ultramassive and compact galaxy at z = 3.35: a detailed look at an early progenitor of local giant ellipticals |
| url | http://hdl.handle.net/20.500.11937/73888 |