Bibcode
Oteo, I.; Bongiovanni, A.; Pérez-García, A. M.; Cepa, J.; Ederoclite, A.; Sánchez-Portal, M.; Pintos-Castro, I.; Pérez-Martínez, R.; Berta, S.; Magnelli, B.; Popesso, P.; Pozzi, F.; Poglitsch, A.; Lutz, D.; Genzel, R.; Tacconi, L.; Förster Schreiber, N.; Sturm, E.; Elbaz, D.; Aussel, H.; Daddi, E.; Andreani, P.; Cimatti, A.; Maiolino, R.; Altieri, B.; Valtchanov, I.
Bibliographical reference
Astronomy and Astrophysics, Volume 541, id.A65
Advertised on:
5
2012
Journal
Citations
25
Refereed citations
24
Description
In this work we analyse the physical properties of a sample of 56
spectroscopically selected star-forming (SF) Lyα emitting galaxies
at 2.0 ≲ z ≲ 3.5 using both a spectral energy distribution
(SED) fitting procedure from rest-frame UV to mid-IR and direct 160
μm FIR observations taken with the Photodetector Array Camera and
Spectrometer (PACS) instrument onboard the Herschel Space Observatory.
We define LAEs as those Lyα-emitting galaxies whose rest-frame
Lyα equivalent widths (Lyα EWrest - frame) are
above 20 Å, the typical threshold in narrow-band searches.
Lyα-emitting galaxies with Lyα EWrest - frame
< 20 Å are called non-LAEs. As a result of an individual SED
fit for each object, we find that the studied sample of LAEs contains
galaxies with ages mostly below 100 Myr and a wide variety of dust
attenuations, SFRs, and stellar masses. The heterogeneity of the
physical properties is also seen in the morphology, ranging from
bulge-like galaxies to highly clumpy systems. In this way, we find that
LAEs at 2.0 ≲ z ≲ 3.5 are very diverse, and do not have a
bimodal nature, as suggested in previous studies. Furthermore, the main
difference between LAEs and non-LAEs is their dust attenuation, because
LAEs are not as dusty as non-LAEs. On the FIR side, four galaxies of the
sample (two LAEs and two non-LAEs) have PACS detections. Their total IR
luminosities place all of them in the ULIRG regime, and all are dusty
objects, with A1200 ≳ 4 mag. This is an indication from
direct FIR measurements that dust and Lyα emission are not
mutually exclusive. This population of red and dusty LAEs is not seen at
z ~ 0.3, which suggests an evolution with redshift of the IR nature of
galaxies selected via their Lyα emission.
Herschel is an ESA space observatory with science instruments provided
by European-led Principal Investigator consortia and with important
participation from NASA.Appendix A is available in electronic form at http://www.aanda.org
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