Lyα at Cosmic Dawn with a Simulated Roman Grism Deep Field
The slitless grism on the Nancy Grace Roman Space Telescope will enable deep near-infrared spectroscopy over a wide field of view. We demonstrate Roman's capability to detect Ly α galaxies at z > 7 using a multiple position angle (PA) observational strategy. We simulate Roman grism data usin...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astronomical Journal |
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| Online Access: | https://doi.org/10.3847/1538-3881/ad2adf |
| _version_ | 1797261502368972800 |
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| author | Isak G. B. Wold Sangeeta Malhotra James E. Rhoads Vithal Tilvi Austen Gabrielpillai |
| author_facet | Isak G. B. Wold Sangeeta Malhotra James E. Rhoads Vithal Tilvi Austen Gabrielpillai |
| author_sort | Isak G. B. Wold |
| collection | DOAJ |
| description | The slitless grism on the Nancy Grace Roman Space Telescope will enable deep near-infrared spectroscopy over a wide field of view. We demonstrate Roman's capability to detect Ly α galaxies at z > 7 using a multiple position angle (PA) observational strategy. We simulate Roman grism data using a realistic foreground scene from the COSMOS field. We also input fake Ly α galaxies spanning redshift z = 7.5–10.5 and a line-flux range of interest. We show how a novel data-cube search technique—CUBGRISM—originally developed for the Galaxy Evolution Explorer can be applied to Roman grism data to produce a Ly α flux-limited sample without the need for continuum detections. We investigate the impact of altering the number of independent PAs and exposure time. A deep Roman grism survey with 25 PAs and a total exposure time of 70 hr can achieve Ly α line depths comparable to the deepest z = 7 narrowband surveys ( L _Ly _α ≳ 10 ^43 erg s ^−1 ). Assuming a null result, where the opacity of the intergalactic medium (IGM) remains unchanged from z ∼ 7, this level of sensitivity will detect ∼400 deg ^−2 Ly α emitters from z = 7.25 to 8.75. A decline from this expected number density is the signature of an increasing neutral hydrogen fraction and the onset of reionization. Our simulations indicate that a deep Roman grism survey has the ability to measure the timing and magnitude of this decline, allowing us to infer the ionization state of the IGM and helping us to distinguish between models of reionization. |
| first_indexed | 2024-04-24T23:42:14Z |
| format | Article |
| id | doaj.art-5bc9e39a90b84906927eb0368ce4698c |
| institution | Directory Open Access Journal |
| issn | 1538-3881 |
| language | English |
| last_indexed | 2024-04-24T23:42:14Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astronomical Journal |
| spelling | doaj.art-5bc9e39a90b84906927eb0368ce4698c2024-03-15T10:13:18ZengIOP PublishingThe Astronomical Journal1538-38812024-01-01167415710.3847/1538-3881/ad2adfLyα at Cosmic Dawn with a Simulated Roman Grism Deep FieldIsak G. B. Wold0https://orcid.org/0000-0002-0784-1852Sangeeta Malhotra1https://orcid.org/0000-0002-9226-5350James E. Rhoads2https://orcid.org/0000-0002-1501-454XVithal Tilvi3https://orcid.org/0000-0001-8514-7105Austen Gabrielpillai4https://orcid.org/0000-0003-4295-3793Astrophysics Science Division, Goddard Space Flight Center , Greenbelt, MD 20771, USA; Department of Physics, The Catholic University of America , Washington, DC 20064, USA; Center for Research and Exploration in Space Science and Technology , NASA/GSFC, Greenbelt, MD 20771, USAAstrophysics Science Division, Goddard Space Flight Center , Greenbelt, MD 20771, USAAstrophysics Science Division, Goddard Space Flight Center , Greenbelt, MD 20771, USASchool of Earth and Space Exploration, Arizona State University , Tempe, AZ 85287, USAAstrophysics Science Division, Goddard Space Flight Center , Greenbelt, MD 20771, USA; Department of Physics, The Catholic University of America , Washington, DC 20064, USA; Center for Research and Exploration in Space Science and Technology , NASA/GSFC, Greenbelt, MD 20771, USAThe slitless grism on the Nancy Grace Roman Space Telescope will enable deep near-infrared spectroscopy over a wide field of view. We demonstrate Roman's capability to detect Ly α galaxies at z > 7 using a multiple position angle (PA) observational strategy. We simulate Roman grism data using a realistic foreground scene from the COSMOS field. We also input fake Ly α galaxies spanning redshift z = 7.5–10.5 and a line-flux range of interest. We show how a novel data-cube search technique—CUBGRISM—originally developed for the Galaxy Evolution Explorer can be applied to Roman grism data to produce a Ly α flux-limited sample without the need for continuum detections. We investigate the impact of altering the number of independent PAs and exposure time. A deep Roman grism survey with 25 PAs and a total exposure time of 70 hr can achieve Ly α line depths comparable to the deepest z = 7 narrowband surveys ( L _Ly _α ≳ 10 ^43 erg s ^−1 ). Assuming a null result, where the opacity of the intergalactic medium (IGM) remains unchanged from z ∼ 7, this level of sensitivity will detect ∼400 deg ^−2 Ly α emitters from z = 7.25 to 8.75. A decline from this expected number density is the signature of an increasing neutral hydrogen fraction and the onset of reionization. Our simulations indicate that a deep Roman grism survey has the ability to measure the timing and magnitude of this decline, allowing us to infer the ionization state of the IGM and helping us to distinguish between models of reionization.https://doi.org/10.3847/1538-3881/ad2adfReionizationLyα galaxiesHigh-redshift galaxiesAstronomical simulationsGalaxy spectroscopy |
| spellingShingle | Isak G. B. Wold Sangeeta Malhotra James E. Rhoads Vithal Tilvi Austen Gabrielpillai Lyα at Cosmic Dawn with a Simulated Roman Grism Deep Field The Astronomical Journal Reionization Lyα galaxies High-redshift galaxies Astronomical simulations Galaxy spectroscopy |
| title | Lyα at Cosmic Dawn with a Simulated Roman Grism Deep Field |
| title_full | Lyα at Cosmic Dawn with a Simulated Roman Grism Deep Field |
| title_fullStr | Lyα at Cosmic Dawn with a Simulated Roman Grism Deep Field |
| title_full_unstemmed | Lyα at Cosmic Dawn with a Simulated Roman Grism Deep Field |
| title_short | Lyα at Cosmic Dawn with a Simulated Roman Grism Deep Field |
| title_sort | lyα at cosmic dawn with a simulated roman grism deep field |
| topic | Reionization Lyα galaxies High-redshift galaxies Astronomical simulations Galaxy spectroscopy |
| url | https://doi.org/10.3847/1538-3881/ad2adf |
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