Site Map
Follow us on Facebook Follow us on Twitter YouTube channel
Centro de Astrofísica da Universidade do Porto

A young star-forming galaxy at z = 3.5 with an extended Lyman α halo seen with MUSE

V. Patrício, J. Richard, A. Verhamme, L. Wisotzki, J. Brinchmann, M. L. Turner, L. Christensen, P. Weilbacher, J. Blaizot, R. Bacon, T. Contini, D. Lagattuta, S. Cantalupo, B. Clément, G. Soucail

Spatially resolved studies of high-redshift galaxies, an essential insight into galaxy formation processes, have been mostly limited to stacking or unusually bright objects. We present here the study of a typical (L*, M = 6 × 109 M) young lensed galaxy at z = 3.5, observed with Multi Unit Spectroscopic Explorer (MUSE), for which we obtain 2D resolved spatial information of Lyα and, for the first time, of C iii] emission. The exceptional signal-to-noise ratio of the data reveals UV emission and absorption lines rarely seen at these redshifts, allowing us to derive important physical properties (Te ∼ 15600 K, ne ∼ 300 cm−3, covering fraction fc ∼ 0.4) using multiple diagnostics. Inferred stellar and gas-phase metallicities point towards a low-metallicity object (Zstellar = ∼0.07 Z and ZISM < 0.16 Z). The Lyα emission extends over ∼10 kpc across the galaxy and presents a very uniform spectral profile, showing only a small velocity shift which is unrelated to the intrinsic kinematics of the nebular emission. The Lyα extension is approximately four times larger than the continuum emission, and makes this object comparable to low-mass LAEs at low redshift, and more compact than the Lyman-break galaxies and Lyα emitters usually studied at high redshift. We model the Lyα line and surface brightness profile using a radiative transfer code in an expanding gas shell, finding that this model provides a good description of both observables.

techniques: imaging spectroscopy – galaxies: abundances – galaxies: high- redshift – galaxies: individual: SMACSJ2031.8-4036

Monthly Notices of the Royal Astronomical Society
Volume 456, Page 4191
March 2016

>> PDF>> ADS>> DOI

Institute of Astrophysics and Space Sciences

Institute of Astrophysics and Space Sciences (IA) is a new but long anticipated research infrastructure with a national dimension. It embodies a bold but feasible vision for the development of Astronomy, Astrophysics and Space Sciences in Portugal, taking full advantage and fully realizing the potential created by the national membership of the European Space Agency (ESA) and the European Southern Observatory (ESO). IA resulted from the merging the two most prominent research units in the field in Portugal: the Centre for Astrophysics of the University of Porto (CAUP) and the Center for Astronomy and Astrophysics of the University of Lisbon (CAAUL). It currently hosts more than two-thirds of all active researchers working in Space Sciences in Portugal, and is responsible for an even greater fraction of the national productivity in international ISI journals in the area of Space Sciences. This is the scientific area with the highest relative impact factor (1.65 times above the international average) and the field with the highest average number of citations per article for Portugal.

Proceed on CAUP's website|Go to IA website