J/A+A/665/A28 Ionizing and heating power of ULXs (Kovlakas+, 2022)
The ionizing and heating power of ultraluminous X-ray sources under the
geometrical beaming model.
Kovlakas K., Fragos T., Schaerer D., Mesinger A.
<Astron. Astrophys. 665, A28 (2022)>
=2022A&A...665A..28K 2022A&A...665A..28K (SIMBAD/NED BibCode)
ADC_Keywords: Accretion ; Binaries, X-ray ; Interstellar medium ;
Extreme UV sources
Keywords: accretion, accretion disks - X-rays: binaries - X-rays: ISM -
X-rays: galaxies - ultraviolet: galaxies
Abstract:
While there is now a consensus that X-ray binaries (XRBs) are the
dominant X-ray sources in the early Universe and play a significant
role during the epoch of heating of the intergalactic medium (IGM),
recent studies report contradicting results regarding their
contribution in the nebular emission of local Universe galaxies.
Ultraluminous X-ray sources (ULXs), which dominate the X-ray budget of
normal galaxies, may be important interstellar-medium (ISM) ionizing
sources. However, their output in the extreme UV (EUV) and soft X-ray
part of the spectrum remains observationally unconstrained. In this
paper, we predict the ionizing and heating power from ULX populations
under the geometrical beaming scenario, and three models describing
the emission from super-critical accretion disks. We find that our
theoretical spectra for ULX populations cannot (can) explain the HeII
(NeV) emission observed in some galaxies, with their contribution
being less (more) important than the underlying stellar population.
Stochastic fluctuations in the number of ULXs may allow for equal
contributions in the HeII emission, in a fraction of galaxies. We
provide average spectra of ULX populations as an input to local, and
early-Universe studies. We find that the soft X-ray emission arising
from super-critical accretion is significant for the heating of the
IGM, and consistent with recent constraints from the 21-cm cosmic
signal. Based on the dependence on the adopted compact-object (CO)
mass and accretion model, we encourage efforts in modeling ULX spectra
via simulations, and their combination with detailed binary population
synthesis models.
Description:
Average ULX spectra scaled by the SFR and metallicity (Z),
corresponding to all nine combinations of CO masses (1.4, 8, and
20M☉), and black-body models (SS73, e_w=0.3, and e_w=0.7). The
spectra of the ULX populations are noramlized for a SFR of
1M☉/yr and solar metallicity.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 130 100000 Average ULX spectra
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 F13.7 eV Energy [0.12/12398.43] Photon energy
15- 22 F8.1 0.1nm lambda [1.0/100000.0] Wavelength (lambda)
24- 34 F11.7 [ph/s] log1.4MSS73 The decimal logarithm of the photon flux
in the (lambda, lambda+1Å) bin for a
ULX population with CO mass 1.4M☉
and spectral model SS73
36- 46 F11.7 [ph/s] log1.4Me_w=0.3 The decimal logarithm of the photon flux
in the (lambda, lambda+1Å) bin for a
ULX population with CO mass 1.4M☉
and spectral model P07 with e_w=0.3
48- 58 F11.7 [ph/s] log1.4Me_w=0.7 The decimal logarithm of the photon flux
in the (lambda, lambda+1Å) bin for a
ULX population with CO mass 1.4M☉
and spectral model P07 with e_w=0.7
60- 70 F11.7 [ph/s] log8.0MSS73 The decimal logarithm of the photon flux
in the (lambda, lambda+1Å) bin for a
ULX population with CO mass 8M☉
and spectral model SS73
72- 82 F11.7 [ph/s] log8.0Me_w=0.3 The decimal logarithm of the photon flux
in the (lambda, lambda+1Å) bin for a
ULX population with CO mass 8M☉
and spectral model P07 with e_w=0.3
84- 94 F11.7 [ph/s] log8.0Me_w=0.7 The decimal logarithm of the photon flux
in the (lambda, lambda+1Å) bin for a
ULX population with CO mass 8M☉
and spectral model P07 with e_w=0.7
96-106 F11.7 [ph/s] log20.0MSS73 The decimal logarithm of the photon flux
in the (lambda, lambda+1Å) bin for a
ULX population with CO mass 20M☉
and spectral model SS73
108-118 F11.7 [ph/s] log20.0Me_w=0.3 The decimal logarithm of the photon flux
in the (lambda, lambda+1Å) bin for a
ULX population with CO mass 20M☉
and spectral model P07 with e_w=0.3
120-130 F11.7 [ph/s] log20.0Me_w=0.7 The decimal logarithm of the photon flux
in the (lambda, lambda+1Å) bin for a
ULX population with CO mass 20M☉
and spectral model P07 with e_w=0.7
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Acknowledgements:
Konstantinos Kovlakas, kkovla(at)gmail.com
(End) Konstantinos Kovlakas [Geneva Univ.], Patricia Vannier [CDS] 21-Jul-2022