---
OA_place: publisher
OA_type: hybrid
_id: '18851'
abstract:
- lang: eng
  text: 'We present volume-limited samples of cataclysmic variables (CVs) and AM CVn
    binaries jointly selected from SRG/eROSITA eRASS1 and Gaia DR3 using an X-ray
    + optical color–color diagram (the "X-ray Main Sequence"). This tool identifies
    all CV subtypes, including magnetic and low-accretion rate systems, in contrast
    to most previous surveys. We find 23 CVs, 3 of which are AM CVns, out to 150 pc
    in the Western Galactic Hemisphere. Our 150 pc sample is spectroscopically verified
    and complete down to LX = 1.3 × 1029 erg s−1 in the 0.2–2.3 keV band, and we also
    present CV candidates out to 300 pc and 1000 pc. We discovered two previously
    unknown systems in our 150 pc sample: the third nearest AM CVn and a magnetic
    period bouncer. We find the mean LX of CVs to be 〈LX〉 ≈ 4.6 × 1030 erg s−1, in
    contrast to previous surveys which yielded 〈LX〉 ∼ 1031−1032 erg s−1. We construct
    X-ray luminosity functions that, for the first time, flatten out at LX ∼ 1030
    erg s−1. We infer average number, mass, and luminosity densities of ρN,CV = (3.7
    ± 0.7) × 10−6pc−3, (math formular), and (math formular), respectively, in the
    solar neighborhood. Our uniform selection method also allows us to place meaningful
    estimates on the space density of AM CVns, ρN,AM CVn = (5.5 ± 3.7) × 10−7 pc−3.
    Magnetic CVs and period bouncers make up 35% and 25% of our sample, respectively.
    This work, through a novel discovery technique, shows that the observed number
    densities of CVs and AM CVns, as well as the fraction of period bouncers, are
    still in tension with population synthesis estimates.'
acknowledgement: "We thank Roman Krivonos for insightful feedback, Kevin Burdge, Dovi
  Poznanski, and Jim Fuller for useful discussions, and Sunny Wong for providing AM
  CVn evolutionary models. A.C.R. acknowledges support from an NSF Graduate Fellowship.\r\n\r\nA.C.R.
  thanks the LSST-DA Data Science Fellowship Program, which is funded by LSST-DA,
  the Brinson Foundation, and the Moore Foundation; his participation in the program
  has benefited this work. RLO is a Research Fellow of the Brazilian institution CNPq
  (PQ-315632/2023-2).\r\n\r\nThis work is based on data from eROSITA, the soft X-ray
  instrument aboard SRG, a joint Russian-German science mission supported by the Russian
  Space Agency (Roskosmos), in the interests of the Russian Academy of Sciences represented
  by its Space Research Institute (IKI), and the Deutsches Zentrum für Luft- und Raumfahrt
  (DLR). The SRG spacecraft was built by Lavochkin Association (NPOL) and its subcontractors,
  and is operated by NPOL with support from the Max Planck Institute for Extraterrestrial
  Physics (MPE). The development and construction of the eROSITA X-ray instrument
  was led by MPE, with contributions from the Dr. Karl Remeis Observatory Bamberg
  & ECAP (FAU Erlangen-Nuernberg), the University of Hamburg Observatory, the Leibniz
  Institute for Astrophysics Potsdam (AIP), and the Institute for Astronomy and Astrophysics
  of the University of Tübingen, with the support of DLR and the Max Planck Society.
  The Argelander Institute for Astronomy of the University of Bonn and the Ludwig
  Maximilians Universität Munich also participated in the science preparation for
  eROSITA.\r\n\r\nThis work presents results from the European Space Agency (ESA)
  space mission Gaia. Gaia data are being processed by the Gaia Data Processing and
  Analysis Consortium (DPAC). Funding for the DPAC is provided by national institutions,
  in particular the institutions participating in the Gaia MultiLateral Agreement
  (MLA). The Gaia mission website is https://www.cosmos.esa.int/gaia. The Gaia archive
  website is https://archives.esac.esa.int/gaia.\r\n\r\nSome of the data presented
  herein were obtained at Keck Observatory, which is a private 501(c)3 non-profit
  organization operated as a scientific partnership among the California Institute
  of Technology, the University of California, and the National Aeronautics and Space
  Administration. The Observatory was made possible by the generous financial support
  of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the
  very significant cultural role and reverence that the summit of Maunakea has always
  had within the Native Hawaiian community. We are most fortunate to have the opportunity
  to conduct observations from this mountain. We are also grateful to the staff of
  Palomar Observatory and that of Lick Observatory for their assistance in carrying
  out observations used in this work.\r\n\r\nBased on observations obtained with the
  Samuel Oschin Telescope 48 inch and the 60 inch Telescope at the Palomar Observatory
  as part of the Zwicky Transient Facility project. ZTF is supported by the National
  Science Foundation under grants No. AST-1440341 and AST-2034437 and a collaboration
  including current partners Caltech, IPAC, the Weizmann Institute of Science, the
  Oskar Klein Center at Stockholm University, the University of Maryland, Deutsches
  Elektronen-Synchrotron and Humboldt University, the TANGO Consortium of Taiwan,
  the University of Wisconsin at Milwaukee, Trinity College Dublin, Lawrence Livermore
  National Laboratories, IN2P3, University of Warwick, Ruhr University Bochum, Northwestern
  University and former partners the University of Washington, Los Alamos National
  Laboratories, and Lawrence Berkeley National Laboratories. Operations are conducted
  by COO, IPAC, and UW.\r\n\r\nSoftware: used: Python and the following libraries:
  matplotlib (Hunter 2007), scipy (Virtanen et al. 2020), astropy (Astropy Collaboration
  et al. 2013), numpy (van der Walt et al. 2011). PypeIt (Prochaska et al. 2020),
  lpipe (Perley 2019), and Tool for OPerations on Catalogues And Tables (TOPCAT) (Taylor
  2005)."
article_number: '014201'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Antonio C.
  full_name: Rodriguez, Antonio C.
  last_name: Rodriguez
- first_name: Kareem
  full_name: El-Badry, Kareem
  last_name: El-Badry
- first_name: Valery
  full_name: Suleimanov, Valery
  last_name: Suleimanov
- first_name: Anna F.
  full_name: Pala, Anna F.
  last_name: Pala
- first_name: Shrinivas R.
  full_name: Kulkarni, Shrinivas R.
  last_name: Kulkarni
- first_name: Boris
  full_name: Gaensicke, Boris
  last_name: Gaensicke
- first_name: Kaya
  full_name: Mori, Kaya
  last_name: Mori
- first_name: R. Michael
  full_name: Rich, R. Michael
  last_name: Rich
- first_name: Arnab
  full_name: Sarkar, Arnab
  last_name: Sarkar
- first_name: Tong
  full_name: Bao, Tong
  last_name: Bao
- first_name: Raimundo Lopes
  full_name: De Oliveira, Raimundo Lopes
  last_name: De Oliveira
- first_name: Gavin
  full_name: Ramsay, Gavin
  last_name: Ramsay
- first_name: Paula
  full_name: Szkody, Paula
  last_name: Szkody
- first_name: Matthew
  full_name: Graham, Matthew
  last_name: Graham
- first_name: Thomas A.
  full_name: Prince, Thomas A.
  last_name: Prince
- first_name: Ilaria
  full_name: Caiazzo, Ilaria
  id: 8ae5b6e7-2a03-11ee-914d-b58ed7a3b47d
  last_name: Caiazzo
  orcid: 0000-0002-4770-5388
- first_name: Zachary P.
  full_name: Vanderbosch, Zachary P.
  last_name: Vanderbosch
- first_name: Jan Van
  full_name: Roestel, Jan Van
  last_name: Roestel
- first_name: Kaustav K.
  full_name: Das, Kaustav K.
  last_name: Das
- first_name: Yu Jing
  full_name: Qin, Yu Jing
  last_name: Qin
- first_name: Mansi M.
  full_name: Kasliwal, Mansi M.
  last_name: Kasliwal
- first_name: Avery
  full_name: Wold, Avery
  last_name: Wold
- first_name: Steven L.
  full_name: Groom, Steven L.
  last_name: Groom
- first_name: Daniel
  full_name: Reiley, Daniel
  last_name: Reiley
- first_name: Reed
  full_name: Riddle, Reed
  last_name: Riddle
citation:
  ama: 'Rodriguez AC, El-Badry K, Suleimanov V, et al. Cataclysmic variables and AM
    CVn binaries in SRG/eROSITA + Gaia: Volume limited samples, X-ray luminosity functions,
    and space densities. <i>Publications of the Astronomical Society of the Pacific</i>.
    2025;137(1). doi:<a href="https://doi.org/10.1088/1538-3873/ada185">10.1088/1538-3873/ada185</a>'
  apa: 'Rodriguez, A. C., El-Badry, K., Suleimanov, V., Pala, A. F., Kulkarni, S.
    R., Gaensicke, B., … Riddle, R. (2025). Cataclysmic variables and AM CVn binaries
    in SRG/eROSITA + Gaia: Volume limited samples, X-ray luminosity functions, and
    space densities. <i>Publications of the Astronomical Society of the Pacific</i>.
    IOP Publishing. <a href="https://doi.org/10.1088/1538-3873/ada185">https://doi.org/10.1088/1538-3873/ada185</a>'
  chicago: 'Rodriguez, Antonio C., Kareem El-Badry, Valery Suleimanov, Anna F. Pala,
    Shrinivas R. Kulkarni, Boris Gaensicke, Kaya Mori, et al. “Cataclysmic Variables
    and AM CVn Binaries in SRG/EROSITA + Gaia: Volume Limited Samples, X-Ray Luminosity
    Functions, and Space Densities.” <i>Publications of the Astronomical Society of
    the Pacific</i>. IOP Publishing, 2025. <a href="https://doi.org/10.1088/1538-3873/ada185">https://doi.org/10.1088/1538-3873/ada185</a>.'
  ieee: 'A. C. Rodriguez <i>et al.</i>, “Cataclysmic variables and AM CVn binaries
    in SRG/eROSITA + Gaia: Volume limited samples, X-ray luminosity functions, and
    space densities,” <i>Publications of the Astronomical Society of the Pacific</i>,
    vol. 137, no. 1. IOP Publishing, 2025.'
  ista: 'Rodriguez AC, El-Badry K, Suleimanov V, Pala AF, Kulkarni SR, Gaensicke B,
    Mori K, Rich RM, Sarkar A, Bao T, De Oliveira RL, Ramsay G, Szkody P, Graham M,
    Prince TA, Caiazzo I, Vanderbosch ZP, Roestel JV, Das KK, Qin YJ, Kasliwal MM,
    Wold A, Groom SL, Reiley D, Riddle R. 2025. Cataclysmic variables and AM CVn binaries
    in SRG/eROSITA + Gaia: Volume limited samples, X-ray luminosity functions, and
    space densities. Publications of the Astronomical Society of the Pacific. 137(1),
    014201.'
  mla: 'Rodriguez, Antonio C., et al. “Cataclysmic Variables and AM CVn Binaries in
    SRG/EROSITA + Gaia: Volume Limited Samples, X-Ray Luminosity Functions, and Space
    Densities.” <i>Publications of the Astronomical Society of the Pacific</i>, vol.
    137, no. 1, 014201, IOP Publishing, 2025, doi:<a href="https://doi.org/10.1088/1538-3873/ada185">10.1088/1538-3873/ada185</a>.'
  short: A.C. Rodriguez, K. El-Badry, V. Suleimanov, A.F. Pala, S.R. Kulkarni, B.
    Gaensicke, K. Mori, R.M. Rich, A. Sarkar, T. Bao, R.L. De Oliveira, G. Ramsay,
    P. Szkody, M. Graham, T.A. Prince, I. Caiazzo, Z.P. Vanderbosch, J.V. Roestel,
    K.K. Das, Y.J. Qin, M.M. Kasliwal, A. Wold, S.L. Groom, D. Reiley, R. Riddle,
    Publications of the Astronomical Society of the Pacific 137 (2025).
date_created: 2025-01-19T23:01:51Z
date_published: 2025-01-01T00:00:00Z
date_updated: 2025-02-27T12:46:32Z
day: '01'
ddc:
- '520'
department:
- _id: IlCa
doi: 10.1088/1538-3873/ada185
external_id:
  arxiv:
  - '2408.16053'
  isi:
  - '001393204700001'
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oa_version: Published Version
publication: Publications of the Astronomical Society of the Pacific
publication_identifier:
  issn:
  - 0004-6280
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Cataclysmic variables and AM CVn binaries in SRG/eROSITA + Gaia: Volume limited
  samples, X-ray luminosity functions, and space densities'
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/3.0/legalcode
  name: Creative Commons Attribution 3.0 Unported (CC BY 3.0)
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