Reconstructing the velocity dispersion profiles from the line-of-sight kinematic data in disc galaxies

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Abstract

We present a modification of the method for reconstructing the stellar velocity ellipsoid (SVE) in disc galaxies. Our version does not need any parametrization of the velocity dispersion profiles and uses only one assumption that the ratio σz/σR remains constant along the profile or along several pieces of the profile. The method was tested on two galaxies from the sample of other authors and for the first time applied to three lenticular galaxies NGC 1167, NGC 3245 and NGC 4150, as well as to one Sab galaxy NGC 338. We found that for galaxies with a high inclination (i >55° - 60°) it is difficult or rather impossible to extract the information about SVE, while for galaxies at an intermediate inclination the procedure of extracting is successful. For NGC 1167 we managed to reconstruct SVE, provided that the value of σz/σR is piecewise constant. We found σz/σR = 0.7 for the inner parts of the disc and σz/σR = 0.3 for the outskirts. We also obtained a rigid constraint on the value of the radial velocity dispersion σR for highly inclined galaxies, and tested the result using the asymmetric-drift equation, provided that the gas rotation curve is available.
Original languageEnglish
Pages (from-to)4956-4967
Number of pages12
JournalMonthly Notices of the Royal Astronomical Society
Volume465
Issue number4
DOIs
StatePublished - 2017

Keywords

    Cite this

    @article{e6b2eb295c0b4d16917f590ac4fed04d,
    title = "Reconstructing the velocity dispersion profiles from the line-of-sight kinematic data in disc galaxies",
    abstract = "We present a modification of the method for reconstructing the stellar velocity ellipsoid (SVE) in disc galaxies. Our version does not need any parametrization of the velocity dispersion profiles and uses only one assumption that the ratio σz/σR remains constant along the profile or along several pieces of the profile. The method was tested on two galaxies from the sample of other authors and for the first time applied to three lenticular galaxies NGC 1167, NGC 3245 and NGC 4150, as well as to one Sab galaxy NGC 338. We found that for galaxies with a high inclination (i >55° - 60°) it is difficult or rather impossible to extract the information about SVE, while for galaxies at an intermediate inclination the procedure of extracting is successful. For NGC 1167 we managed to reconstruct SVE, provided that the value of σz/σR is piecewise constant. We found σz/σR = 0.7 for the inner parts of the disc and σz/σR = 0.3 for the outskirts. We also obtained a rigid constraint on the value of the radial velocity dispersion σR for highly inclined galaxies, and tested the result using the asymmetric-drift equation, provided that the gas rotation curve is available.",
    keywords = "galaxies: fundamental parameters, galaxies: kinematics and dynamics",
    author = "Сотникова, {наталья Яковлевна} and Марчук, {Александр Александрович}",
    year = "2017",
    doi = "10.1093/mnras/stw3092",
    language = "English",
    volume = "465",
    pages = "4956--4967",
    journal = "Monthly Notices of the Royal Astronomical Society",
    issn = "0035-8711",
    publisher = "Wiley-Blackwell",
    number = "4",

    }

    TY - JOUR

    T1 - Reconstructing the velocity dispersion profiles from the line-of-sight kinematic data in disc galaxies

    AU - Сотникова, наталья Яковлевна

    AU - Марчук, Александр Александрович

    PY - 2017

    Y1 - 2017

    N2 - We present a modification of the method for reconstructing the stellar velocity ellipsoid (SVE) in disc galaxies. Our version does not need any parametrization of the velocity dispersion profiles and uses only one assumption that the ratio σz/σR remains constant along the profile or along several pieces of the profile. The method was tested on two galaxies from the sample of other authors and for the first time applied to three lenticular galaxies NGC 1167, NGC 3245 and NGC 4150, as well as to one Sab galaxy NGC 338. We found that for galaxies with a high inclination (i >55° - 60°) it is difficult or rather impossible to extract the information about SVE, while for galaxies at an intermediate inclination the procedure of extracting is successful. For NGC 1167 we managed to reconstruct SVE, provided that the value of σz/σR is piecewise constant. We found σz/σR = 0.7 for the inner parts of the disc and σz/σR = 0.3 for the outskirts. We also obtained a rigid constraint on the value of the radial velocity dispersion σR for highly inclined galaxies, and tested the result using the asymmetric-drift equation, provided that the gas rotation curve is available.

    AB - We present a modification of the method for reconstructing the stellar velocity ellipsoid (SVE) in disc galaxies. Our version does not need any parametrization of the velocity dispersion profiles and uses only one assumption that the ratio σz/σR remains constant along the profile or along several pieces of the profile. The method was tested on two galaxies from the sample of other authors and for the first time applied to three lenticular galaxies NGC 1167, NGC 3245 and NGC 4150, as well as to one Sab galaxy NGC 338. We found that for galaxies with a high inclination (i >55° - 60°) it is difficult or rather impossible to extract the information about SVE, while for galaxies at an intermediate inclination the procedure of extracting is successful. For NGC 1167 we managed to reconstruct SVE, provided that the value of σz/σR is piecewise constant. We found σz/σR = 0.7 for the inner parts of the disc and σz/σR = 0.3 for the outskirts. We also obtained a rigid constraint on the value of the radial velocity dispersion σR for highly inclined galaxies, and tested the result using the asymmetric-drift equation, provided that the gas rotation curve is available.

    KW - galaxies: fundamental parameters, galaxies: kinematics and dynamics

    U2 - 10.1093/mnras/stw3092

    DO - 10.1093/mnras/stw3092

    M3 - Article

    VL - 465

    SP - 4956

    EP - 4967

    JO - Monthly Notices of the Royal Astronomical Society

    JF - Monthly Notices of the Royal Astronomical Society

    SN - 0035-8711

    IS - 4

    ER -