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Related papers: Constraining the Contribution of Galaxies and Acti…

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The origin of obscuration in Active Galactic Nuclei (AGN) is still an open debate. In particular, it is unclear what drives the relative contributions to the line-of-sight column densities from galaxy-scale and torus-linked obscuration. The…

The effects of Active Galactic Nuclei (AGNs) on their host-galaxies depend on the coupling between the injected energy and the interstellar medium (ISM). Here, we model and quantify the impact of long-range AGN ionizing radiation -- in…

Astrophysics of Galaxies · Physics 2015-02-09 Orianne Roos , Stéphanie Juneau , Frédéric Bournaud , Jared M. Gabor

We present measurements of the specific ultraviolet luminosity density from a sample of 483 galaxies at 6<z<8. These galaxies were selected from new deep near-infrared HST imaging from the CANDELS, HUDF09 and ERS programs. In contrast to…

The protagonists of cosmic reionization remain elusive. Faint star-forming galaxies are leading candidates because they are numerous and may have significant ionizing photon escape fractions ($f_{esc}$). Here we update this picture via an…

Astrophysics of Galaxies · Physics 2020-04-07 Rohan P. Naidu , Sandro Tacchella , Charlotte A. Mason , Sownak Bose , Pascal A. Oesch , Charlie Conroy

We build a simple physical model to study the high-redshift active galactic Nucleus (AGN) evolution within the co-evolution framework of central black holes (BHs) and their host galaxies. The correlation between the circular velocity of a…

Astrophysics of Galaxies · Physics 2016-09-21 Jirong Mao , Minsun Kim

We derive astroparticle constraints in different dark matter scenarios alternative to cold dark matter (CDM): thermal relic warm dark matter, WDM; fuzzy dark matter, $\psi$DM; self-interacting dark matter, SIDM; sterile neutrino dark…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-13 A. Lapi , T. Ronconi , L. Boco , F. Shankar , N. Krachmalnicoff , C. Baccigalupi , L. Danese

How do galaxies of different luminosities contribute to the metal absorber populations of varying species and strength? We present our analysis of the predicted metal contributions from galaxies as observed in quasar absorption line spectra…

Astrophysics of Galaxies · Physics 2024-08-16 Samir Kušmić , Kristian Finlator , Ezra Huscher , Maya Steen

We present a semi-analytic model for the thermal and ionization history of the universe at 1000 >~ z >~ 3. This model incorporates much of the essential physics included in full-scale hydrodynamical simulations, such as (1) gravitational…

Astrophysics · Physics 2009-10-31 Weihsueh A. Chiu , Jeremiah P. Ostriker

Ionization cones and relativistic jets give us one of the most large-scale example of active galactic nuclei (AGN) influence on the surrounding gas environment in galaxies and beyond. The study of ionization cones makes it possible not only…

Astrophysics of Galaxies · Physics 2023-12-05 Alexei V. Moiseev , Aleksandrina A. Smirnova

The great power offered by photoionization models of Active Galactic Nuclei (AGN) emission-line regions has long been mitigated by the fact that very little is known about the spectral energy distribution (SED) between the Lyman limit,…

High Energy Astrophysical Phenomena · Physics 2020-05-13 Gary Ferland , Chris Done , Chichuan Jin , Hermine Landt , Martin Ward

We have evaluated the contribution of the AGN population to the ionization history of the Universe based on a semi-analytic model of galaxy formation and evolution in the CDM cosmological scenario. The model connects the growth of black…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 E. Giallongo , N. Menci , F. Fiore , M. Castellano , A. Fontana , A. Grazian , L. Pentericci

In order to derive the AGN contribution to the cosmological ionizing emissivity we have selected faint AGN candidates at $z>4$ in the CANDELS GOODS-South field which is one of the deepest fields with extensive multiwavelength coverage from…

We describe improved modelling of the emission by dust in a toroidal--like structure heated by a central illuminating source within Active Galactic Nuclei (AGN). We chose a simple but realistic torus geometry, a flared disc, and a dust…

Astrophysics · Physics 2009-11-13 J. Fritz , A. Franceschini , E. Hatziminaoglou

We combine deep X-ray survey data from the Chandra observatory and the wide-area/shallow XMM-XXL field to estimate the AGN X-ray luminosity function in the redshift range z=3-5. The sample consists of nearly 340 sources with either…

Cosmic reionization holds the key to understand structure formation in the Universe, and can inform us about the properties of the first sources, as their star formation efficiency and escape fraction of ionizing photons. By combining the…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-07 Sourav Mitra , T. Roy Choudhury , Andrea Ferrara

We use Herschel-PACS far-infrared data, combined with previous multi-band information and mid-IR spectra, to properly account for the presence of an active nucleus and constrain its energetic contribution in luminous infrared (IR) sources…

The new Wide Field Camera 3/IR observations on the Hubble Ultra-Deep Field started investigating the properties of galaxies during the reionization epoch. To interpret these observations, we present a novel approach inspired by the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 M. Trenti , M. Stiavelli , R. J. Bouwens , P. Oesch , J. M. Shull , G. D. Illingworth , L. D. Bradley , C. M. Carollo

We study the observed cosmic ionizing background as a constraint on the nature of the sources responsible for the reionization of the Universe. In earlier work, we showed that extrapolations of the Ultra-Violet Luminosity Function (LF) of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Fabio Fontanot , Stefano Cristiani , Christoph Pfrommer , Guido Cupani , Eros Vanzella

At Cosmic Noon ($z\approx 2-3$), both star formation and Active Galactic Nuclei (AGN) activity peaked, each playing a significant role in ionizing interstellar gas on galaxy-wide scales. The spatial distribution of this ionized gas provides…

Observations of the Epoch of Reionization (EoR) have the potential to answer long-standing questions of astrophysical interest regarding the nature of the first luminous sources and their effects on the intergalactic medium (IGM). We…