Related papers: Identifying Lyman Alpha Emitters powered by AGNs
The Lyman-alpha emitters found at z=4.5 and 5.7 by the Large Area Lyman Alpha (LALA) survey have high equivalent widths in the Lyman-alpha line. Such lines can be produced by narrow-lined active galactic nuclei (AGNs) or by stellar…
Active Galactic Nuclei (AGN) are highly energetic astrophysical sources powered by accretion onto supermassive black holes in galaxies, which present unique observational signatures covering the full electromagnetic spectrum (and more) over…
We present optical spectroscopy of two samples of GALEX grism selected Ly alpha emitters (LAEs): one at z=0.195-0.44 and the other at z=0.65-1.25. We have also observed a comparison sample of galaxies in the same redshift intervals with the…
The analysis of the physical properties of low-redshift Ly$\alpha$ emitters (LAEs) can provide clues in the study of their high-redshift analogues. At $z \sim 0.3$, LAEs are bright enough to be detected over almost the entire…
We present the results of a 400ks Chandra survey of 29 extended Ly-alpha emitting nebulae (Ly-alpha Blobs, LABs) in the z=3.09 proto-cluster in the SSA22 field. We detect luminous X-ray counterparts in five LABs, implying a large fraction…
Narrowband imaging is a highly successful approach for finding large numbers of high redshift Lya emitting galaxies (LAEs) up to z~6.6. However, at z>~7 there are as yet only 3 narrowband selected LAEs with spectroscopic confirmations (two…
Addressing how strong UV radiation affects galaxy formation is central to understanding their evolution. The quenching of star formation via strong UV radiation (from starbursts or AGN) has been proposed in various scenes to solve certain…
Ly$\alpha$-emitting galaxies (LAEs) are easily detectable in the high-redshift Universe and are potentially efficient tracers of large scale structure at early epochs, as long as their observed properties do not strongly depend on…
We have used the VLBA at 5 GHz to observe all galaxies with nuclear radio flux densities above 3.5 mJy found in a VLA survey at 15 GHz of a sample of nearby LINER galaxies. All galaxies were detected revealing high brightness temperature…
As part of a large spectroscopic survey of z>5 Lyman break galaxies (LBGs), we have identified a single source which is clearly hosting an AGN. Out of a sample of more than fifty spectroscopically-confirmed R-band dropout galaxies at z~5…
The GALEX (Galaxy Evolution Explorer) spectroscopic survey mode, with a resolution of about 8 A in the FUV (1350 - 1750 A) and about 20 A in the NUV (1950 - 2750 A) is used for a systematic search of Ly-a emitting galaxies at low redshift.…
We have carried out a search for Lyman alpha emission from galaxies at z~=2.4 over a field of 1200 sq. arcmin using the CFH12K camera at the CFHT and a custom medium band filter. The search has uncovered 58 candidates, corresponding to a…
Some cosmological hydrodynamical simulations predict that outflows driven by active galactic nuclei (AGN) play a key role in powering the Ly$\alpha$ nebulae observed around high-redshift quasars. In such simulations, AGN feedback seeded as…
We report results of a unprecedentedly deep, blind search for Ly-alpha emitters (LAEs) at z = 5.7 using IMACS, the Inamori-Magellan Areal Camera & Spectrograph, with the goal of identifying missing sources of reionization that could also be…
We report the discovery of a Lyman alpha emitting galaxy at z = 6.518. The single line was found in the 43 square arcmin VLT/FORS field by slitless spectroscopy limited to the atmospheric window at 9100 A (sampling Lya at 6.4 < z < 6.6).…
We present a large sample of infrared-luminous candidate active galactic nuclei (AGNs) that lack X-ray detections in Chandra, XMM-Newton, and NuSTAR fields. We selected all optically detected SDSS sources with redshift measurements,…
Several studies have detected Lyman-alpha (Ly$\alpha$) from bright ($M_\mathrm{UV}\lesssim-21.5$) galaxies during the early stages of reionization despite the significantly neutral intergalactic medium. To explain these detections, it has…
In this paper we discuss the contribution of different astrophysical sources to the ionization of neutral hydrogen at different redshifts. We critically revise the arguments in favour/against a substantial contribution of Active Galactic…
We present results from a blind, spectroscopic survey for redshift ~5.7 Lyman-alpha-emitting galaxies using the Inamori Magellan Areal Camera and Spectrograph. A total of ~200 square arcminutes were observed in the COSMOS and LCIRS fields…
We quantify the presence of Active Galactic nuclei (AGN) in a mass-complete (M_* >5e10 M_sun) sample of 123 star-forming and quiescent galaxies at 1.5 < z < 2.5, using X-ray data from the 4 Ms Chandra Deep Field-South (CDF-S) survey.…