Are the accretion states of AGNs and
XRBs analogous?
Abhijeet Borkar
Jiri Svoboda, Peter Boorman, Emily Moravec, Daniel Kynoch
Masaryk University
Brno, Czechia
20th
February 2023
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Bachelor (BSc) and Master (MSc) astronomy students
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Work in Czechia, Hungary, Poland, Slovakia.
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IAU-International Visegrad Fund Mobility Award
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Deadline: April 23rd
2023, 23:59 CET
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1 page motivation letter & CV.
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Meeting of ALMA Young Astronomers
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All astronomical subjects, ALMA observing modes,
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Fully online, interaction with ALMA staff, social events.
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Ongoing Projects
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AGN in Dwarf Galaxies
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Multifrequency observations of Green Pea and Blueberry galaxies.
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AGN Feedback
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Interaction between AGN emission & surrounding medium (Borkar+21; 23-in-prep.)
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Feeding AGN
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Studying the impact of galaxy mergers on SMBH growth & AGN activity.
Are the accretion states of AGNs and
XRBs analogous?
Merloni et al. (2003)
The Hardness-Intensity Diagram
Hardness =
Lhard
Lsoft
+ Lhard
LPL
Ldisk
+ LPL
=
High accretion mode:
0.1 – 1 LEdd
, dominated by thermal disk
blackbody emission.
Low accretion mode:
<0.01 LEdd
, advection dominated
emission, power-law spectrum in hard
X-rays
The Hardness-Intensity Diagram
Based on Fender et al. (2004)
The Hardness-Intensity Diagram
Dunn et al. (2010)
The Hardness-Intensity Diagram for AGNs
Direct comparison between XRBs and AGNs is not straightforward.
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The accretion disk is larger, lower in temperature, and located further away.
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Disk emission peaks in UV band, while the X-ray is dominated by power-law.
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Timescales ~ 105
years, instead of few hundred days.
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AGN masses span four orders of magnitude → Eddington ratio instead of luminosity.
Catalogue Compilation
1. Cross-match 4XMM and OMC5 with same RA-DEC and OBSID.
2. Cross-match with Veron-Cetty & Veron (2010) and SDSS DR14
AGN/quasar catalogs to get confirmed AGN.
3. Cross-match with VLA-FIRST and VLASS radio catalogs to get radio
fluxes.
4. Quality cuts for: UV extension, UV detection significance, exposure, Xray
obscuration. Remove: blazars, z < 0.001 sources.
5. Same procedure for BAT AGN Spectroscopic Survey (BASS) sources.
Estimating Luminosity
Total luminosity:
Ltot
= LX
+ LUV
LX
: 0.1 – 100 keV luminosity obtained from extrapolating 2-10 keV flux.
LUV
: obtained from estimating the slope of UV flux in OMC fluxes.
BH mass obtained from SDSS DR 16 BH mass catalog (Rakshit et al.
2020)
Svoboda et al. (2017)
Catalogue Compilation

Host galaxy subtraction:
1. Estimate SFR from X-ray and UV luminosity, and remove SF
contribution to total luminosity.
2. Moves sources to right and bottom.
Dunn et al (2010)
Radio Properties
RL = LR
/Ltot
= LR
/(LX
+ LUV
)
Moravec et al. (2022)
Moravec et al. (2022)
FR­I
FR­II
RL Quasars
RQ Quasars
Seyfert Type
Narrow line Seyfert 1
Intermediate Seyferts
LINERs
Fernandez-Ontiveros &
Munoz-Darias (2021)
Host Galaxy Properties
Changing Look AGN
Changing Look AGN
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AGN which have been caught changing from
one Seyfert type to another.
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Or changing from Compton thick to
Compton thin (or the other way round).
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Change timescales of months to decades.
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Long timescales cannot be explained by
simple change in obscuration.
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Require changes in the accretion process to
explain the behaviour.
Ruan et al. 2019a
Conclusions:
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Stellar mass BHs in XRBs and SMBHs in AGNs have similar accretion states.
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Numerous quasars in the XMM-Newton sample are in the high-soft state.
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Many low-luminosity AGN from the BASS sample are in the low-hard state.
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Radio-loud sources are predominantly in the hard part of the HID.
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The radio morphology and excitation classes occupy different places in the HID.
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The position within HID and host galaxy properties are correlated, suggesting a
possible coevolution of AGN and host galaxy.
Contact me at:
abhijeetborkar.com
borkar@asu.cas.cz
Working Group(s):
ALMA Czech node: asu.cas.cz/alma
Relativistic Astrophysics: astro.cas.cz
Prague AGN: pragueagn.wordpress.com
●
Applications open NOW!
●
Deadline: April 23rd
2023, 23:59 CET
●
1 page motivation letter & CV.
●
All details at
https://www.iau.org/science/grants_prizes/iau-visegrad/
Or scan the QR code
IAU-International Visegrad Fund Mobility Award
Extra Slides
Extra Slides