Issue |
A&A
Volume 653, September 2021
|
|
---|---|---|
Article Number | A24 | |
Number of page(s) | 12 | |
Section | Extragalactic astronomy | |
DOI | https://doi.org/10.1051/0004-6361/202140353 | |
Published online | 03 September 2021 |
The OTELO survey
Revealing a population of low-luminosity active star-forming galaxies at z ∼ 0.9
1
Asociación Astrofísica para la Promoción de la Investigación, Instrumentación y su Desarrollo, ASPID, 38205 La Laguna, Tenerife, Spain
e-mail: rocina01@ucm.es
2
Centro de Astrobiología (CSIC/INTA), ESAC Campus, 28692 Villanueva de la Cañada, Madrid, Spain
3
ISDEFE for European Space Astronomy Centre (ESAC)/ESA, PO Box 78, 28690 Villanueva de la Cañada, Madrid, Spain
4
Departamento de Física de la Tierra y Astrofísica, Instituto de Física de Partículas y del Cosmos, IPARCOS, Universidad Complutense de Madrid, 28040 Madrid, Spain
5
Instituto de Radioastronomía Milimétrica (IRAM), Av. Divina Pastora 7, Núcleo Central, 18012 Granada, Spain
6
Geneva Observatory, University of Geneva, Ch. des Maillettes 51, 1290 Versoix, Switzerland
7
RAL Space, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, UK
8
ESAC, European Space Astronomy Center, 28691 Villanueva de la Cañada, Spain
9
Instituto de Astrofísica de Canarias (IAC), 38200 La Laguna, Tenerife, Spain
10
Departamento de Astrofísica, Universidad de La Laguna (ULL), 38205 La Laguna, Tenerife, Spain
11
Instituto de Astrofísica de Andalucía, CSIC, 18080 Granada, Spain
12
Departamento de Física, Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, Mexico D.F., Mexico
13
Instituto de Astronomía, Universidad Nacional Autónoma de México, Apdo. Postal 70-264, 04510 Ciudad de México, Mexico
14
Instituto de Física de Cantabria (CSIC-Universidad de Cantabria), 39005 Santander, Spain
15
Armagh Observatory and Planetarium, College Hill, Armagh BT61 DG, UK
16
INAF, Telescopio Nazionale Galileo, Apartado de Correos 565, 38700 Santa Cruz de la Palma, Spain
17
Fundación Galileo Galilei – INAF Rambla Jos, Ana Fernández Pérez, 7, 38712 Breña Baja, Tenerife, Spain
Received:
14
January
2021
Accepted:
13
May
2021
Aims. We study a sample of Hβ emission line sources at z ∼ 0.9 to identify the star-forming galaxies sample and characterise them in terms of line luminosity, stellar mass, star formation rate, and morphology. The final aim is to obtain the Hβ luminosity function of the star-forming galaxies at this redshift.
Methods. We used the red tunable filter of the instrument Optical System for Imaging low Resolution Integrated Spectroscopy (OSIRIS) at Gran Telescopio de Canarias to obtain the pseudo spectra of emission line sources in the OTELO field. From these pseudo spectra, we identified the objects with Hβ emission. As the resolution of the pseudo spectra allowed us to separate Hβ from [O III], we were able to derive the Hβ flux without contamination from its adjacent line. Using data from the extended OTELO catalogue, we discriminated AGNs and studied the star formation rate, the stellar mass, and the morphology of the star-forming galaxies.
Results. We find that our sample is located on the main sequence of star-forming galaxies. The sources are morphologically classified, mostly as disc-like galaxies (76%), and 90% of the sample are low-mass galaxies (M* < 1010 M⊙). The low-mass star-forming galaxies at z ∼ 0.9 that were detected by OTELO present similar properties as low-mass star-forming galaxies in the local universe, suggesting that these kinds of objects do not have a favorite epoch of formation and star formation enhancement from z ∼ 1 to now. Our sample of 40 Hβ star-forming galaxies include the faintest Hβ emitters detected so far. This allows us to constrain the faint end of the luminosity function for the Hβ line alone with a minimum luminosity of log L = 39 erg s−1, which is a hundred times fainter than previous surveys. The dust-corrected OSIRIS Tunable Emission Line Object survey (OTELO) Hβ luminosity function established the faint-end slope as α = −1.36 ± 0.15. We increased the scope of the analysis to the bright end by adding ancillary data from the literature, which was not dust-corrected in this case. The obtained slope for this extended luminosity function is α = −1.43 ± 0.12.
Key words: galaxies: star formation / galaxies: luminosity function / mass function / surveys / cosmology: observations / catalogs / techniques: imaging spectroscopy
© ESO 2021
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.