NuSTAR observations of water megamaser AGN

A. Masini, A. Comastri, M. Baloković, Ingyin Zaw, S. Puccetti, D. R. Ballantyne, F. E. Bauer, S. E. Boggs, W. N. Brandt, M. Brightman, F. E. Christensen, W. W. Craig, P. Gandhi, C. J. Hailey, F. A. Harrison, M. J. Koss, G. Madejski, C. Ricci, E. Rivers, D. Stern & 1 others W. W. Zhang

    Research output: Contribution to journalArticle

    Abstract

    Aims. We study the connection between the masing disk and obscuring torus in Seyfert 2 galaxies. Methods. We present a uniform X-ray spectral analysis of the high energy properties of 14 nearby megamaser active galactic nuclei observed by NuSTAR. We use a simple analytical model to localize the maser disk and understand its connection with the torus by combining NuSTAR spectral parameters with the available physical quantities from VLBI mapping. Results. Most of the sources that we analyzed are heavily obscured, showing a column density in excess of ∼1023 cm-2; in particular, 79% are Compton-thick (NH > 1.5 × 1024 cm-2). When using column densities measured by NuSTAR with the assumption that the torus is the extension of the maser disk, and further assuming a reasonable density profile, we can predict the torus dimensions. They are found to be consistent with mid-IR interferometry parsec-scale observations of Circinus and NGC 1068. In this picture, the maser disk is intimately connected to the inner part of the torus. It is probably made of a large number of molecular clouds that connect the torus and the outer part of the accretion disk, giving rise to a thin disk rotating in most cases in Keplerian or sub-Keplerian motion. This toy model explains the established close connection between water megamaser emission and nuclear obscuration as a geometric effect.

    Original languageEnglish (US)
    Article numberA59
    JournalAstronomy and Astrophysics
    Volume589
    DOIs
    StatePublished - May 1 2016

    Fingerprint

    masers
    water
    very long baseline interferometry
    interferometry
    spectral analysis
    very long base interferometry
    rotating disks
    occultation
    molecular clouds
    accretion
    active galactic nuclei
    accretion disks
    spectrum analysis
    galaxies
    energy
    profiles
    x rays
    effect
    method
    parameter

    Keywords

    • galaxies: active
    • galaxies: Seyfert
    • masers

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Space and Planetary Science

    Cite this

    Masini, A., Comastri, A., Baloković, M., Zaw, I., Puccetti, S., Ballantyne, D. R., ... Zhang, W. W. (2016). NuSTAR observations of water megamaser AGN. Astronomy and Astrophysics, 589, [A59]. https://doi.org/10.1051/0004-6361/201527689

    NuSTAR observations of water megamaser AGN. / Masini, A.; Comastri, A.; Baloković, M.; Zaw, Ingyin; Puccetti, S.; Ballantyne, D. R.; Bauer, F. E.; Boggs, S. E.; Brandt, W. N.; Brightman, M.; Christensen, F. E.; Craig, W. W.; Gandhi, P.; Hailey, C. J.; Harrison, F. A.; Koss, M. J.; Madejski, G.; Ricci, C.; Rivers, E.; Stern, D.; Zhang, W. W.

    In: Astronomy and Astrophysics, Vol. 589, A59, 01.05.2016.

    Research output: Contribution to journalArticle

    Masini, A, Comastri, A, Baloković, M, Zaw, I, Puccetti, S, Ballantyne, DR, Bauer, FE, Boggs, SE, Brandt, WN, Brightman, M, Christensen, FE, Craig, WW, Gandhi, P, Hailey, CJ, Harrison, FA, Koss, MJ, Madejski, G, Ricci, C, Rivers, E, Stern, D & Zhang, WW 2016, 'NuSTAR observations of water megamaser AGN', Astronomy and Astrophysics, vol. 589, A59. https://doi.org/10.1051/0004-6361/201527689
    Masini A, Comastri A, Baloković M, Zaw I, Puccetti S, Ballantyne DR et al. NuSTAR observations of water megamaser AGN. Astronomy and Astrophysics. 2016 May 1;589. A59. https://doi.org/10.1051/0004-6361/201527689
    Masini, A. ; Comastri, A. ; Baloković, M. ; Zaw, Ingyin ; Puccetti, S. ; Ballantyne, D. R. ; Bauer, F. E. ; Boggs, S. E. ; Brandt, W. N. ; Brightman, M. ; Christensen, F. E. ; Craig, W. W. ; Gandhi, P. ; Hailey, C. J. ; Harrison, F. A. ; Koss, M. J. ; Madejski, G. ; Ricci, C. ; Rivers, E. ; Stern, D. ; Zhang, W. W. / NuSTAR observations of water megamaser AGN. In: Astronomy and Astrophysics. 2016 ; Vol. 589.
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    abstract = "Aims. We study the connection between the masing disk and obscuring torus in Seyfert 2 galaxies. Methods. We present a uniform X-ray spectral analysis of the high energy properties of 14 nearby megamaser active galactic nuclei observed by NuSTAR. We use a simple analytical model to localize the maser disk and understand its connection with the torus by combining NuSTAR spectral parameters with the available physical quantities from VLBI mapping. Results. Most of the sources that we analyzed are heavily obscured, showing a column density in excess of ∼1023 cm-2; in particular, 79{\%} are Compton-thick (NH > 1.5 × 1024 cm-2). When using column densities measured by NuSTAR with the assumption that the torus is the extension of the maser disk, and further assuming a reasonable density profile, we can predict the torus dimensions. They are found to be consistent with mid-IR interferometry parsec-scale observations of Circinus and NGC 1068. In this picture, the maser disk is intimately connected to the inner part of the torus. It is probably made of a large number of molecular clouds that connect the torus and the outer part of the accretion disk, giving rise to a thin disk rotating in most cases in Keplerian or sub-Keplerian motion. This toy model explains the established close connection between water megamaser emission and nuclear obscuration as a geometric effect.",
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    author = "A. Masini and A. Comastri and M. Baloković and Ingyin Zaw and S. Puccetti and Ballantyne, {D. R.} and Bauer, {F. E.} and Boggs, {S. E.} and Brandt, {W. N.} and M. Brightman and Christensen, {F. E.} and Craig, {W. W.} and P. Gandhi and Hailey, {C. J.} and Harrison, {F. A.} and Koss, {M. J.} and G. Madejski and C. Ricci and E. Rivers and D. Stern and Zhang, {W. W.}",
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    T1 - NuSTAR observations of water megamaser AGN

    AU - Masini, A.

    AU - Comastri, A.

    AU - Baloković, M.

    AU - Zaw, Ingyin

    AU - Puccetti, S.

    AU - Ballantyne, D. R.

    AU - Bauer, F. E.

    AU - Boggs, S. E.

    AU - Brandt, W. N.

    AU - Brightman, M.

    AU - Christensen, F. E.

    AU - Craig, W. W.

    AU - Gandhi, P.

    AU - Hailey, C. J.

    AU - Harrison, F. A.

    AU - Koss, M. J.

    AU - Madejski, G.

    AU - Ricci, C.

    AU - Rivers, E.

    AU - Stern, D.

    AU - Zhang, W. W.

    PY - 2016/5/1

    Y1 - 2016/5/1

    N2 - Aims. We study the connection between the masing disk and obscuring torus in Seyfert 2 galaxies. Methods. We present a uniform X-ray spectral analysis of the high energy properties of 14 nearby megamaser active galactic nuclei observed by NuSTAR. We use a simple analytical model to localize the maser disk and understand its connection with the torus by combining NuSTAR spectral parameters with the available physical quantities from VLBI mapping. Results. Most of the sources that we analyzed are heavily obscured, showing a column density in excess of ∼1023 cm-2; in particular, 79% are Compton-thick (NH > 1.5 × 1024 cm-2). When using column densities measured by NuSTAR with the assumption that the torus is the extension of the maser disk, and further assuming a reasonable density profile, we can predict the torus dimensions. They are found to be consistent with mid-IR interferometry parsec-scale observations of Circinus and NGC 1068. In this picture, the maser disk is intimately connected to the inner part of the torus. It is probably made of a large number of molecular clouds that connect the torus and the outer part of the accretion disk, giving rise to a thin disk rotating in most cases in Keplerian or sub-Keplerian motion. This toy model explains the established close connection between water megamaser emission and nuclear obscuration as a geometric effect.

    AB - Aims. We study the connection between the masing disk and obscuring torus in Seyfert 2 galaxies. Methods. We present a uniform X-ray spectral analysis of the high energy properties of 14 nearby megamaser active galactic nuclei observed by NuSTAR. We use a simple analytical model to localize the maser disk and understand its connection with the torus by combining NuSTAR spectral parameters with the available physical quantities from VLBI mapping. Results. Most of the sources that we analyzed are heavily obscured, showing a column density in excess of ∼1023 cm-2; in particular, 79% are Compton-thick (NH > 1.5 × 1024 cm-2). When using column densities measured by NuSTAR with the assumption that the torus is the extension of the maser disk, and further assuming a reasonable density profile, we can predict the torus dimensions. They are found to be consistent with mid-IR interferometry parsec-scale observations of Circinus and NGC 1068. In this picture, the maser disk is intimately connected to the inner part of the torus. It is probably made of a large number of molecular clouds that connect the torus and the outer part of the accretion disk, giving rise to a thin disk rotating in most cases in Keplerian or sub-Keplerian motion. This toy model explains the established close connection between water megamaser emission and nuclear obscuration as a geometric effect.

    KW - galaxies: active

    KW - galaxies: Seyfert

    KW - masers

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