_version_ 1866915980578390016
author Rankine, Amy L.
Homan, David
Aird, James
Hiremath, Pranavi
Anderson, Scott F.
Assef, Roberto J.
Bauer, Franz E.
Brandt, W. N.
Brusa, Marcella
Buchner, Johannes
Chira, Maria
Díaz, Yaherlyn
Hall, Patrick B.
Koekemoer, Anton M.
Krumpe, Mirko
Lamer, Georg
Liu, Teng
Morrison, Sean
Musiimenta, Blessing
Negrete, C. A.
Ni, Qingling
Hidalgo, Paola Rodríguez
Salvato, Mara
Schneider, Donald P.
Shen, Yue
Temple, Matthew J.
Tubín-Arenas, Dusán
Wylezalek, Dominika
author_facet Rankine, Amy L.
Homan, David
Aird, James
Hiremath, Pranavi
Anderson, Scott F.
Assef, Roberto J.
Bauer, Franz E.
Brandt, W. N.
Brusa, Marcella
Buchner, Johannes
Chira, Maria
Díaz, Yaherlyn
Hall, Patrick B.
Koekemoer, Anton M.
Krumpe, Mirko
Lamer, Georg
Liu, Teng
Morrison, Sean
Musiimenta, Blessing
Negrete, C. A.
Ni, Qingling
Hidalgo, Paola Rodríguez
Salvato, Mara
Schneider, Donald P.
Shen, Yue
Temple, Matthew J.
Tubín-Arenas, Dusán
Wylezalek, Dominika
contents We present an investigation of the rest-frame optical/UV and X-ray properties for a sample of 3027 X-ray selected quasars between $1.5 \leq z \leq 3.5$ detected in the deepest Spectrum Roentgen Gamma/eROSITA data available and observed by the fifth iteration of the Sloan Digital Sky Survey (SDSS-V). We parametrize the CIV$\lambda1549$ emission line to infer the strength of accretion disc winds and perform X-ray spectral fitting. The X-ray spectral properties -- namely, the 2keV monochromatic luminosity (L$_\text{2keV}$) and spectral slope -- are not strongly correlated with wind strength. Despite this result, the X-ray selected sample is shifted towards lower CIV blueshifts and higher equivalent widths than the optically selected sample observed in previous SDSS surveys, and matching in optical luminosity, redshift, and Eddington ratio does not reduce these differences. We estimate the far-UV luminosity using the HeII$\lambda1640$ line luminosity and define the slopes between this and the 2500A monochromatic luminosity ($L_{2500}$) and L$_\text{2keV}$ ($α_\text{ouv}$ and $α_\text{uvx}$, respectively) in a similar manner to the familiar $α_\text{ox}$ parameter, which tracks the spectral slope between $L_{2500}$ and L$_\text{2keV}$. The quantity $α_\text{ouv}$ is more strongly correlated with wind strength in our sample than $α_\text{ox}$. We show that the correlation between $α_\text{ox}$ and wind strength is driven by the relationship between the optical luminosity and wind strength. Our results are consistent with a radiation line-driven wind, whereby the ionising far-UV photons must not over-ionise the gas. The hard X-ray photons are few enough in number to have a negligible effect on the ionisation state of the material.
format Preprint
id arxiv_https___arxiv_org_abs_2603_15075
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle CIV wind properties of the SDSS-V X-ray selected quasars: strong optical-to-UV emission is key regardless of X-ray strength
Rankine, Amy L.
Homan, David
Aird, James
Hiremath, Pranavi
Anderson, Scott F.
Assef, Roberto J.
Bauer, Franz E.
Brandt, W. N.
Brusa, Marcella
Buchner, Johannes
Chira, Maria
Díaz, Yaherlyn
Hall, Patrick B.
Koekemoer, Anton M.
Krumpe, Mirko
Lamer, Georg
Liu, Teng
Morrison, Sean
Musiimenta, Blessing
Negrete, C. A.
Ni, Qingling
Hidalgo, Paola Rodríguez
Salvato, Mara
Schneider, Donald P.
Shen, Yue
Temple, Matthew J.
Tubín-Arenas, Dusán
Wylezalek, Dominika
Astrophysics of Galaxies
High Energy Astrophysical Phenomena
We present an investigation of the rest-frame optical/UV and X-ray properties for a sample of 3027 X-ray selected quasars between $1.5 \leq z \leq 3.5$ detected in the deepest Spectrum Roentgen Gamma/eROSITA data available and observed by the fifth iteration of the Sloan Digital Sky Survey (SDSS-V). We parametrize the CIV$\lambda1549$ emission line to infer the strength of accretion disc winds and perform X-ray spectral fitting. The X-ray spectral properties -- namely, the 2keV monochromatic luminosity (L$_\text{2keV}$) and spectral slope -- are not strongly correlated with wind strength. Despite this result, the X-ray selected sample is shifted towards lower CIV blueshifts and higher equivalent widths than the optically selected sample observed in previous SDSS surveys, and matching in optical luminosity, redshift, and Eddington ratio does not reduce these differences. We estimate the far-UV luminosity using the HeII$\lambda1640$ line luminosity and define the slopes between this and the 2500A monochromatic luminosity ($L_{2500}$) and L$_\text{2keV}$ ($α_\text{ouv}$ and $α_\text{uvx}$, respectively) in a similar manner to the familiar $α_\text{ox}$ parameter, which tracks the spectral slope between $L_{2500}$ and L$_\text{2keV}$. The quantity $α_\text{ouv}$ is more strongly correlated with wind strength in our sample than $α_\text{ox}$. We show that the correlation between $α_\text{ox}$ and wind strength is driven by the relationship between the optical luminosity and wind strength. Our results are consistent with a radiation line-driven wind, whereby the ionising far-UV photons must not over-ionise the gas. The hard X-ray photons are few enough in number to have a negligible effect on the ionisation state of the material.
title CIV wind properties of the SDSS-V X-ray selected quasars: strong optical-to-UV emission is key regardless of X-ray strength
topic Astrophysics of Galaxies
High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2603.15075