Effect of Extinction on Quasar Luminosity Distances Determined from UV and X-Ray Flux Measurements
In Khadka et al., a sample of X-ray-detected reverberation-mapped quasars was presented and applied for the comparison of cosmological constraints inferred using two well-established relations in active galactic nuclei—the X-ray/UV luminosity ( L _X – L _UV ) relation and the broad-line region radiu...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2024-01-01
|
| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/ad11dc |
| _version_ | 1797337912721801216 |
|---|---|
| author | Michal Zajaček Bożena Czerny Narayan Khadka Mary Loli Martínez-Aldama Raj Prince Swayamtrupta Panda Bharat Ratra |
| author_facet | Michal Zajaček Bożena Czerny Narayan Khadka Mary Loli Martínez-Aldama Raj Prince Swayamtrupta Panda Bharat Ratra |
| author_sort | Michal Zajaček |
| collection | DOAJ |
| description | In Khadka et al., a sample of X-ray-detected reverberation-mapped quasars was presented and applied for the comparison of cosmological constraints inferred using two well-established relations in active galactic nuclei—the X-ray/UV luminosity ( L _X – L _UV ) relation and the broad-line region radius–luminosity ( R – L ) relation. L _X – L _UV and R – L luminosity distances to the same quasars exhibit a distribution of their differences that is generally asymmetric and positively shifted for the six cosmological models we consider. We demonstrate that this behavior can be interpreted qualitatively as arising as a result of the dust extinction of UV/X-ray quasar emission. We show that the extinction always contributes to the nonzero difference between L _X – L _UV -based and R – L -based luminosity distances and we derive a linear relationship between the X-ray/UV color index E _X _−UV and the luminosity-distance difference, which also depends on the value of the L _X – L _UV relation slope. Taking into account the median and the peak values of the luminosity-distance difference distributions, the average X-ray/UV color index falls in the range of ${\overline{E}}_{X-\mathrm{UV}}=0.03\mbox{--}0.28$ mag for the current sample of 58 sources. This amount of extinction is typical for the majority of quasars and can be attributed to the circumnuclear and interstellar media of host galaxies. After applying the standard hard X-ray and far-UV extinction cuts, heavily extincted sources are removed but overall the shift toward positive values persists. The effect of extinction on luminosity distances is more pronounced for the L _X – L _UV relation since the extinction of UV and X-ray emissions both contribute. |
| first_indexed | 2024-03-08T09:23:27Z |
| format | Article |
| id | doaj.art-df6f045becba4b9d9388a841b9d21fc7 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-08T09:23:27Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-df6f045becba4b9d9388a841b9d21fc72024-01-31T11:23:16ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-01961222910.3847/1538-4357/ad11dcEffect of Extinction on Quasar Luminosity Distances Determined from UV and X-Ray Flux MeasurementsMichal Zajaček0https://orcid.org/0000-0001-6450-1187Bożena Czerny1https://orcid.org/0000-0001-5848-4333Narayan Khadka2https://orcid.org/0000-0001-5512-2716Mary Loli Martínez-Aldama3https://orcid.org/0000-0002-7843-7689Raj Prince4https://orcid.org/0000-0002-1173-7310Swayamtrupta Panda5https://orcid.org/0000-0002-5854-7426Bharat Ratra6https://orcid.org/0000-0002-7307-0726Department of Theoretical Physics and Astrophysics, Faculty of Science, Masaryk University , Kotlářská 2, 611 37 Brno, Czech Republic ; zajacek@physics.muni.czCenter for Theoretical Physics , Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, PolandDepartment of Physics, Bellarmine University , 2001 Newburg Rd, Louisville, KY 40205, USA; Department of Physics and Astronomy, Stony Brook University , Stony Brook, NY 11794, USAAstronomy Department, Universidad de Concepción , Casilla 160-C, Concepción 4030000, Chile; Instituto de Física y Astronomía, Facultad de Ciencias, Universidad de Valparaíso , Gran Bretaña 1111, Playa Ancha, Valparaíso, ChileCenter for Theoretical Physics , Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, PolandLaboratório Nacional de Astrofísica—MCTI , R. dos Estados Unidos, 154—Nações, Itajubá—MG, 37504-364, BrazilDepartment of Physics, Kansas State University , 116 Cardwell Hall, Manhattan, KS 66506, USAIn Khadka et al., a sample of X-ray-detected reverberation-mapped quasars was presented and applied for the comparison of cosmological constraints inferred using two well-established relations in active galactic nuclei—the X-ray/UV luminosity ( L _X – L _UV ) relation and the broad-line region radius–luminosity ( R – L ) relation. L _X – L _UV and R – L luminosity distances to the same quasars exhibit a distribution of their differences that is generally asymmetric and positively shifted for the six cosmological models we consider. We demonstrate that this behavior can be interpreted qualitatively as arising as a result of the dust extinction of UV/X-ray quasar emission. We show that the extinction always contributes to the nonzero difference between L _X – L _UV -based and R – L -based luminosity distances and we derive a linear relationship between the X-ray/UV color index E _X _−UV and the luminosity-distance difference, which also depends on the value of the L _X – L _UV relation slope. Taking into account the median and the peak values of the luminosity-distance difference distributions, the average X-ray/UV color index falls in the range of ${\overline{E}}_{X-\mathrm{UV}}=0.03\mbox{--}0.28$ mag for the current sample of 58 sources. This amount of extinction is typical for the majority of quasars and can be attributed to the circumnuclear and interstellar media of host galaxies. After applying the standard hard X-ray and far-UV extinction cuts, heavily extincted sources are removed but overall the shift toward positive values persists. The effect of extinction on luminosity distances is more pronounced for the L _X – L _UV relation since the extinction of UV and X-ray emissions both contribute.https://doi.org/10.3847/1538-4357/ad11dcCosmologyCosmological parametersObservational cosmologyActive galaxiesQuasarsInterstellar dust extinction |
| spellingShingle | Michal Zajaček Bożena Czerny Narayan Khadka Mary Loli Martínez-Aldama Raj Prince Swayamtrupta Panda Bharat Ratra Effect of Extinction on Quasar Luminosity Distances Determined from UV and X-Ray Flux Measurements The Astrophysical Journal Cosmology Cosmological parameters Observational cosmology Active galaxies Quasars Interstellar dust extinction |
| title | Effect of Extinction on Quasar Luminosity Distances Determined from UV and X-Ray Flux Measurements |
| title_full | Effect of Extinction on Quasar Luminosity Distances Determined from UV and X-Ray Flux Measurements |
| title_fullStr | Effect of Extinction on Quasar Luminosity Distances Determined from UV and X-Ray Flux Measurements |
| title_full_unstemmed | Effect of Extinction on Quasar Luminosity Distances Determined from UV and X-Ray Flux Measurements |
| title_short | Effect of Extinction on Quasar Luminosity Distances Determined from UV and X-Ray Flux Measurements |
| title_sort | effect of extinction on quasar luminosity distances determined from uv and x ray flux measurements |
| topic | Cosmology Cosmological parameters Observational cosmology Active galaxies Quasars Interstellar dust extinction |
| url | https://doi.org/10.3847/1538-4357/ad11dc |
| work_keys_str_mv | AT michalzajacek effectofextinctiononquasarluminositydistancesdeterminedfromuvandxrayfluxmeasurements AT bozenaczerny effectofextinctiononquasarluminositydistancesdeterminedfromuvandxrayfluxmeasurements AT narayankhadka effectofextinctiononquasarluminositydistancesdeterminedfromuvandxrayfluxmeasurements AT marylolimartinezaldama effectofextinctiononquasarluminositydistancesdeterminedfromuvandxrayfluxmeasurements AT rajprince effectofextinctiononquasarluminositydistancesdeterminedfromuvandxrayfluxmeasurements AT swayamtruptapanda effectofextinctiononquasarluminositydistancesdeterminedfromuvandxrayfluxmeasurements AT bharatratra effectofextinctiononquasarluminositydistancesdeterminedfromuvandxrayfluxmeasurements |