X-Ray View of Little Red Dots: Do They Host Supermassive Black
Holes?

J 2024

X-Ray View of Little Red Dots: Do They Host Supermassive Black Holes?

ANANNA, Tonima Tasnim, Akos BOGDAN, Orsolya Eszter KOVÁCS, Priyamvada NATARAJAN, Ryan C. HICKOX et. al.

Základní údaje

Originální název

X-Ray View of Little Red Dots: Do They Host Supermassive Black Holes?

Autoři

ANANNA, Tonima Tasnim, Akos BOGDAN, Orsolya Eszter KOVÁCS (348 Maďarsko, domácí), Priyamvada NATARAJAN a Ryan C. HICKOX

Vydání

Astrophysical Journal Letters, IOP Publishing Ltd, 2024, 2041-8205

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10308 Astronomy

Stát vydavatele

Velká Británie a Severní Irsko

Utajení

není předmětem státního či obchodního tajemství

Odkazy

URL

Impakt faktor

Impact factor: 7.900 v roce 2022

Organizační jednotka

Přírodovědecká fakulta

DOI

http://dx.doi.org/10.3847/2041-8213/ad5669

UT WoS

001260083600001

Klíčová slova anglicky

Active galactic nuclei; James Webb Space Telescope; X-ray active galactic nuclei; Supermassive black holes

Štítky

rivok

Příznaky

Mezinárodní význam, Recenzováno

Změněno: 18. 7. 2024 09:43, Mgr. Marie Šípková, DiS.

Anotace

V originále

The discovery of Little Red Dots (LRDs)—a population of compact, high-redshift, dust-reddened galaxies—is one of the most surprising results from JWST. However, the nature of LRDs is still debated: does the near-infrared emission originate from accreting supermassive black holes (SMBHs), or intense star formation? In this work, we utilize ultra-deep Chandra observations and study LRDs residing behind the lensing galaxy cluster, A2744. We probe the X-ray emission from individual galaxies but find that they remain undetected and provide SMBH mass upper limits of ≲(1.5–16) × 106M⊙ assuming Eddington limited accretion. To increase the signal-to-noise ratios, we conduct a stacking analysis of the full sample with a total lensed exposure time of ≈87 Ms. We also bin the galaxies based on their stellar mass, lensing magnification, and detected broad-line Hα emission. For the LRDs exhibiting broad-line Hα emission, there is a hint of a stacked signal (∼2.6σ), corresponding to an SMBH mass of ∼3.2 × 106M⊙. Assuming unobscured, Eddington-limited accretion, this black hole (BH) mass is at least 1.5 orders of magnitude lower than that inferred from virial mass estimates using JWST spectra. Given galaxy-dominated stellar mass estimates, our results imply that LRDs do not host overmassive SMBHs and/or accrete at a few percent of their Eddington limit. However, alternative stellar mass estimates may still support that LRDs host overmassive BHs. The significant discrepancy between the JWST and Chandra data hints that the scaling relations used to infer the SMBH mass from the Hα line and virial relations may not be applicable for high-redshift LRDs.

Návaznosti

GX21-13491X, projekt VaV

Název: Zkoumání žhavého vesmíru a porozumění kosmické zpětné vazbě (Akronym: EHU)

Investor: Grantová agentura ČR, Exploring the Hot Universe and Understanding Comic Feedback

Citovat

ANANNA, Tonima Tasnim, Akos BOGDAN, Orsolya Eszter KOVÁCS, Priyamvada NATARAJAN a Ryan C. HICKOX. X-Ray View of Little Red Dots: Do They Host Supermassive Black Holes? Astrophysical Journal Letters. IOP Publishing Ltd, 2024, roč. 969, č. 1, s. 1-10. ISSN 2041-8205. Dostupné z: https://dx.doi.org/10.3847/2041-8213/ad5669.

@article{2418981,
   author = {Ananna, Tonima Tasnim and Bogdan, Akos and Kovács, Orsolya Eszter and Natarajan, Priyamvada and Hickox, Ryan C.},
   article_number = {1},
   doi = {http://dx.doi.org/10.3847/2041-8213/ad5669},
   keywords = {Active galactic nuclei; James Webb Space Telescope; X-ray active galactic nuclei; Supermassive black holes},
   language = {eng},
   issn = {2041-8205},
   journal = {Astrophysical Journal Letters},
   title = {X-Ray View of Little Red Dots: Do They Host Supermassive Black Holes?},
   url = {https://iopscience.iop.org/article/10.3847/2041-8213/ad5669},
   volume = {969},
   year = {2024}
}

TY  - JOUR
ID  - 2418981
AU  - Ananna, Tonima Tasnim - Bogdan, Akos - Kovács, Orsolya Eszter - Natarajan, Priyamvada - Hickox, Ryan C.
PY  - 2024
TI  - X-Ray View of Little Red Dots: Do They Host Supermassive Black Holes?
JF  - Astrophysical Journal Letters
VL  - 969
IS  - 1
SP  - 1-10
EP  - 1-10
PB  - IOP Publishing Ltd
SN  - 20418205
KW  - Active galactic nuclei
KW  - James Webb Space Telescope
KW  - X-ray active galactic nuclei
KW  - Supermassive black holes
UR  - https://iopscience.iop.org/article/10.3847/2041-8213/ad5669
N2  - The discovery of Little Red Dots (LRDs)—a population of compact, high-redshift, dust-reddened galaxies—is one of the most surprising results from JWST. However, the nature of LRDs is still debated: does the near-infrared emission originate from accreting supermassive black holes (SMBHs), or intense star formation? In this work, we utilize ultra-deep Chandra observations and study LRDs residing behind the lensing galaxy cluster, A2744. We probe the X-ray emission from individual galaxies but find that they remain undetected and provide SMBH mass upper limits of ≲(1.5–16) × 106M⊙ assuming Eddington limited accretion. To increase the signal-to-noise ratios, we conduct a stacking analysis of the full sample with a total lensed exposure time of ≈87 Ms. We also bin the galaxies based on their stellar mass, lensing magnification, and detected broad-line Hα emission. For the LRDs exhibiting broad-line Hα emission, there is a hint of a stacked signal (∼2.6σ), corresponding to an SMBH mass of ∼3.2 × 106M⊙. Assuming unobscured, Eddington-limited accretion, this black hole (BH) mass is at least 1.5 orders of magnitude lower than that inferred from virial mass estimates using JWST spectra. Given galaxy-dominated stellar mass estimates, our results imply that LRDs do not host overmassive SMBHs and/or accrete at a few percent of their Eddington limit. However, alternative stellar mass estimates may still support that LRDs host overmassive BHs. The significant discrepancy between the JWST and Chandra data hints that the scaling relations used to infer the SMBH mass from the Hα line and virial relations may not be applicable for high-redshift LRDs.
ER  -

ANANNA, Tonima Tasnim, Akos BOGDAN, Orsolya Eszter KOVÁCS, Priyamvada NATARAJAN a Ryan C. HICKOX. X-Ray View of Little Red Dots: Do They Host Supermassive Black Holes? \textit{Astrophysical Journal Letters}. IOP Publishing Ltd, 2024, roč.~969, č.~1, s.~1-10. ISSN~2041-8205. Dostupné z: https://dx.doi.org/10.3847/2041-8213/ad5669.

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