The NuSTAR local AGN N H distribution survey (NuLANDS). I. Toward a truly representative column density distribution in the local universe

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F25%3A00604207" target="_blank" >RIV/67985815:_____/25:00604207 - isvavai.cz</a>

Výsledek na webu

<a href="https://hdl.handle.net/11104/0365909" target="_blank" >https://hdl.handle.net/11104/0365909</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/ad8236" target="_blank" >10.3847/1538-4357/ad8236</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The NuSTAR local AGN N H distribution survey (NuLANDS). I. Toward a truly representative column density distribution in the local universe

Popis výsledku v původním jazyce

Hard X-ray-selected samples of active galactic nuclei (AGN) provide one of the cleanest views of supermassive black hole accretion but are biased against objects obscured by Compton-thick gas column densities of N-H > 10(24) cm(-2). To tackle this issue, we present the NuSTAR Local AGN N-H Distribution Survey (NuLANDS)-a legacy sample of 122 nearby (z < 0.044) AGN primarily selected to have warm infrared colors from IRAS between 25 and 60 mu m. We show that optically classified Type 1 and 2 AGN in NuLANDS are indistinguishable in terms of optical [O iii] line flux and mid-to-far-infrared AGN continuum bolometric indicators, as expected from an isotropically selected AGN sample, while Type 2 AGN are deficient in terms of their observed hard X-ray flux. By testing many X-ray spectroscopic models, we show the measured line-of-sight column density varies on average by similar to 1.4 orders of magnitude depending on the obscurer geometry. To circumvent such issues, we propagate the uncertainties per source into the parent column density distribution, finding a directly measured Compton-thick fraction of 35% +/- 9%. By construction, our sample will miss sources affected by severe narrow-line reddening, and thus segregates sources dominated by small-scale nuclear obscuration from large-scale host-galaxy obscuration. This bias implies an even higher intrinsic obscured AGN fraction may be possible, although tests for additional biases arising from our infrared selection find no strong effects on the measured column density distribution. NuLANDS thus holds potential as an optimized sample for future follow-up with current and next-generation instruments aiming to study the local AGN population in an isotropic manner.

Název v anglickém jazyce

The NuSTAR local AGN N H distribution survey (NuLANDS). I. Toward a truly representative column density distribution in the local universe

Popis výsledku anglicky

Hard X-ray-selected samples of active galactic nuclei (AGN) provide one of the cleanest views of supermassive black hole accretion but are biased against objects obscured by Compton-thick gas column densities of N-H > 10(24) cm(-2). To tackle this issue, we present the NuSTAR Local AGN N-H Distribution Survey (NuLANDS)-a legacy sample of 122 nearby (z < 0.044) AGN primarily selected to have warm infrared colors from IRAS between 25 and 60 mu m. We show that optically classified Type 1 and 2 AGN in NuLANDS are indistinguishable in terms of optical [O iii] line flux and mid-to-far-infrared AGN continuum bolometric indicators, as expected from an isotropically selected AGN sample, while Type 2 AGN are deficient in terms of their observed hard X-ray flux. By testing many X-ray spectroscopic models, we show the measured line-of-sight column density varies on average by similar to 1.4 orders of magnitude depending on the obscurer geometry. To circumvent such issues, we propagate the uncertainties per source into the parent column density distribution, finding a directly measured Compton-thick fraction of 35% +/- 9%. By construction, our sample will miss sources affected by severe narrow-line reddening, and thus segregates sources dominated by small-scale nuclear obscuration from large-scale host-galaxy obscuration. This bias implies an even higher intrinsic obscured AGN fraction may be possible, although tests for additional biases arising from our infrared selection find no strong effects on the measured column density distribution. NuLANDS thus holds potential as an optimized sample for future follow-up with current and next-generation instruments aiming to study the local AGN population in an isotropic manner.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

<a href="/cs/project/GA22-22643S" target="_blank" >GA22-22643S: Galaktická gastronomie: Hrášky a Borůvky</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Astrophysical Journal

ISSN

0004-637X

e-ISSN

1538-4357

Svazek periodika

978

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

60

Strana od-do

118

Kód UT WoS článku

001389155800001

EID výsledku v databázi Scopus

2-s2.0-85215574462