Evidence for a Rotational Component in the Circumgalactic Medium of Nearby Galaxies
| العنوان: | Evidence for a Rotational Component in the Circumgalactic Medium of Nearby Galaxies |
|---|---|
| المؤلفون: | Bart P. Wakker, David M. French |
| سنة النشر: | 2020 |
| مصطلحات موضوعية: | Physics, 010504 meteorology & atmospheric sciences, Relative velocity, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Galaxy, Luminosity, Galactic halo, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Halo, Impact parameter, 010303 astronomy & astrophysics, Galaxy rotation curve, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences |
| الوصف: | We present results of a study comparing the relative velocity of $\rm Ly\alpha$ absorbers to the rotation velocity of nearby galaxy disks in the local universe ($z \leq 0.03$). We have obtained rotation curves via long-slit spectroscopy of eight galaxies with the Southern African Large Telescope, and combine this dataset with an additional 16 galaxies with data from the literature. Each galaxy appears within $3R_{\rm vir}$ of a QSO sightline with archival Cosmic Origin Spectrograph (COS) spectra. We study the velocity orientation of absorbers with respect to nearby galaxy's rotation, and compare with results from both the Steidel et al. (2002) monolithic halo model and a new cylindrical Navarro-Frenk-White galaxy halo model to interpret these data in the context of probing 3D galaxy halos via 1D QSO absorption-line spectroscopy. Relative to these models we find that up to $59\pm5\%$ of $\rm Ly\alpha$ absorbers have velocities consistent with co-rotation. We find the $\rm Ly\alpha$ co-rotation fraction to decrease with galaxy luminosity ($L^*$) and impact parameter in a model-independent fashion. We report that both anti-rotating absorbers and those found near luminous galaxies ($L \gtrsim 0.5 L^*$) mostly have low Doppler $b$-parameters ($b \lesssim 50$ km $\rm s^{-1}$). Absorbers consistent with co-rotation show a wide range of Doppler $b$-parameters. Finally, we find a strong anticorrelation between co-rotation fraction and galaxy inclination, which is at odds with recent metal-line kinematic studies and suggests the kinematic and geometric distribution of the circumgalactic medium is complex and multiphase. Comment: 27 pages, 17 figures, accepted to ApJ |
| اللغة: | English |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c2dae7477bacd7541bd06d80b46bc058 http://arxiv.org/abs/2006.09323 |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....c2dae7477bacd7541bd06d80b46bc058 |
| قاعدة البيانات: | OpenAIRE |
| الوصف غير متاح. |