Galaxy gas as obscurer: I. GRBs x-ray galaxies and find a N_H ~ M* relation

Abstract

An important constraint for galaxy evolution models is how much gas resides in galaxies, in particular at the peak of star formation z=1-3. We attempt a novel approach by letting long-duration Gamma Ray Bursts (LGRBs) x-ray their host galaxies and deliver column densities to us. This requires a good understanding of the obscurer and biases introduced by incomplete follow-up observations. We analyse the X-ray afterglow of all 844 Swift LGRBs to date for their column density $N_H$. To derive the population properties we propagate all uncertainties in a consistent Bayesian methodology. The $N_H$ distribution covers the $10^{20-23}{\mathrm{cm}}^{-2}$ range and shows no evolutionary effect. Higher obscurations, e.g. Compton-thick columns, could have been detected but are not observed. The $N_H$ distribution is consistent with sources randomly populating a ellipsoidal gas cloud of major axis $N_H^{\text{major}}=10^{23}{\mathrm{cm}}^{-2}$ with 0.22 dex intrinsic scatter between objects. The unbiased SHOALS survey of afterglows and hosts allows us to constrain the relation between Spitzer-derived stellar masses and X-ray derived column densities $N_H$. We find a well-constrained powerlaw relation of $N_H=10^{21.7}{\mathrm{cm}}^{-2}\times {\left(M_{\star }/10^{9.5}{M}_{\odot }\right)}^{1/3}$, with 0.5 dex intrinsic scatter between objects. The Milky Way and the Magellanic clouds also follow this relation. From the geometry of the obscurer, its stellar mass dependence and comparison with local galaxies we conclude that LGRBs are primarily obscured by galaxy-scale gas. Ray tracing of simulated Illustris galaxies reveals a relation of the same normalisation, but a steeper stellar-mass dependence and mild redshift evolution. Our new approach provides valuable insight into the gas residing in high-redshift galaxies.

Accepted in MNRAS. Video presentation: https://vimeo.com/188434334 Easy-to-read write-up: http://astrost.at/istics/how-to-xray-galaxies.html

References in corpus (18)

• Cosmic Star Formation History
• Introducing the Illustris Project: Simulating the coevolution of dark and visible matter in the Universe
• The Supernova -- Gamma-Ray Burst Connection
• Properties of galaxies reproduced by a hydrodynamic simulation
• Introducing the Illustris Project: the evolution of galaxy populations across cosmic time
• Long gamma-ray bursts and core-collapse supernovae have different environments
• Toward the Standard Population Synthesis Model of the X-Ray Background: Evolution of X-Ray Luminosity and Absorption Functions of Active Galactic Nuclei Including Compton-Thick Populations
• The Resolved Properties of Extragalactic Giant Molecular Clouds
• Obscuration-dependent evolution of Active Galactic Nuclei
• The First Swift BAT Gamma-Ray Burst Catalog
• The optically unbiased GRB host (TOUGH) survey. III. Redshift distribution
• GRB 130925A: an ultra-long Gamma Ray Burst with a dust-echo afterglow, and implications for the origin of the ultra-long GRBs
• The optically unbiased GRB host (TOUGH) survey. V. VLT/X-shooter emission-line redshifts for Swift GRBs at z~2
• A Flexible Method of Estimating Luminosity Functions
• GRB 120711A: an intense INTEGRAL burst with long-lasting soft gamma-ray emission and a powerful optical flash
• Kinematical Structure of the Magellanic System
• Gas and Metal Contents of Galaxies and Gaseous Halos: Preventive versus Ejective Feedback
• Properties of Low Luminosity Afterglow Gamma-ray Bursts

Cited by in corpus (25)

• Active Galactic Nuclei: what's in a name?
• The ASTRID simulation: the evolution of Supermassive Black Holes
• Supermassive Black Holes at High Redshift are Expected to be Obscured by their Massive Host Galaxies' Inter Stellar Medium
• A hard X-ray view of Luminous and Ultra-luminous Infrared Galaxies in GOALS: I - AGN obscuration along the merger sequence
• Fundamental differences in the radio properties of red and blue quasars: evolution strongly favoured over orientation
• The Host-Galaxy Properties of Type 1 Versus Type 2 Active Galactic Nuclei
• Illuminating the dark side of cosmic star formation two billion years after the Big Bang
• BASS XXXVII: The role of radiative feedback in the growth and obscuration properties of nearby supermassive black holes
• Galaxy properties of type 1 and 2 X-ray selected AGN and comparison among different classification criteria
• Physically motivated X-ray obscurer models
• Dust reddening and extinction curves towards gamma-ray bursts at z > 4
• A panchromatic view of infrared quasars: excess star formation and radio emission in the most heavily obscured systems
• Do Radio Active Galactic Nuclei Reflect X-ray Binary Spectral States?
• Host Dark Matter Halos of WISE-selected Obscured & Unobscured Quasars: Evidence for Evolution
• The Obscured Fraction of Quasars at Cosmic Noon
• Accretion properties of X-ray AGN: Evidence for radiation-regulated obscuration with redshift-dependent host galaxy contribution
• The LOFAR-eFEDS survey: The incidence of radio and X-ray AGN and the disk-jet connection
• Using realistic host galaxy metallicities to improve the GRB X-ray equivalent total hydrogen column density and constrain the intergalactic medium density
• The eROSITA Final Equatorial Depth Survey (eFEDS): the hard X-ray selected sample
• Probing the physical properties of the intergalactic medium using gamma-ray bursts
• X-ray absorbing column densities of a complete sample of short Gamma Ray Bursts
• Probing the roles of orientation and multi-scale gas distributions in shaping the obscuration of Active Galactic Nuclei through cosmic time
• Probing the physical properties of the intergalactic medium using blazars
• A simple model of dust extinction in gamma-ray burst host galaxies
• Dense gas linked to star-forming regions photoionised by embedded gamma-ray bursts