Dynamics of Molecular Gas in the Central Region of the Quasar IZwicky1

Abstract

We present a study of the molecular gas distribution and kinematics in the cicumnuclear region (radii $\lesssim 2$kpc) of the $z\approx 0.061$ quasar IZwicky1 using a collection of available Atacama Large Millimeter/submillimeter Array (ALMA) observations of the carbon monoxide (CO) emission. With an angular resolution of $\sim 0.36^{\prime \prime }$ (corresponding to $\sim 400\mathrm{pc}$), the host galaxy sub-structures including the nuclear molecular gas disk, spiral arms, and a compact bar-like component are resolved. We analyzed the gas kinematics based on the CO image cube and obtained the rotation curve and radial distribution of velocity dispersion. The velocity dispersion is about $30\mathrm{km}{\mathrm{s}}^{-1}$ in the outer CO disk region and rises up to $\gtrsim 100\mathrm{km}{\mathrm{s}}^{-1}$ at radius $\lesssim 1$kpc, suggesting that the central region of disk is dynamically hot. We constrain the CO-to-${\mathrm{H}}_2$ conversion factor, ${\alpha }_{\mathrm{CO}}$, by modeling the cold gas disk dynamics. We find that, with prior knowledge about the stellar and dark matter components, the ${\alpha }_{\mathrm{CO}}$ value in the circumnuclear region of this quasar host galaxy is $1.55_{-0.49}^{+0.47}{M}_{\odot }{\left(\mathrm{K}\mathrm{km}{\mathrm{s}}^{-1}\mathrm{p}{\mathrm{c}}^2\right)}^{-1}$, which is between the value reported in ultra-luminous infrared galaxies and in the Milky-Way. The central 1kpc region of this quasar host galaxy has significant star formation activity, which can be identified as a nuclear starburst. We further investigate the high velocity dispersion in the central region. We find that the ISM turbulent pressure derived from the gas velocity dispersion is in equilibrium with the weight of the ISM. This argues against extra power from AGN feedback that significantly affects the kinematics of the cold molecular gas.

20 pages, 10 figures. Accepted for publication in ApJ

References in corpus (35)

• The NumPy array: a structure for efficient numerical computation
• Some Aspects of Measurement Error in Linear Regression of Astronomical Data
• High-Resolution Rotation Curves and Galaxy Mass Models from THINGS
• Massive molecular outflows and negative feedback in ULIRGs observed by Herschel-PACS
• xCOLD GASS: the complete IRAM-30m legacy survey of molecular gas for galaxy evolution studies
• CO excitation of normal star forming galaxies out to z=1.5 as regulated by the properties of their interstellar medium
• Spitzer Quasar and ULIRG evolution study (QUEST): I. The origin of the far infrared continuum of QSOs
• 2MASS wide field extinction maps - I. The Pipe nebula
• Molecular Gas Properties on Cloud Scales Across the Local Star-forming Galaxy Population
• Revisiting the Integrated Star Formation Law. Paper I: Non-Starbursting Galaxies
• New Constraints on the ${}^{12}$CO(2-1)/(1-0) Line Ratio Across Nearby Disc Galaxies
• Revisiting the Integrated Star Formation Law. II. Starbursts and the Combined Global Schmidt Law
• Pressure-Regulated, Feedback-Modulated Star Formation In Disk Galaxies
• Dense Molecular Gas and the Role of Star Formation in the Host Galaxies of Quasi-Stellar Objects
• AGN Feedback and Star Formation of Quasar Host Galaxies: Insights from the Molecular Gas
• BAT AGN Spectroscopic Survey-XX: Molecular Gas in Nearby Hard X-ray Selected AGN Galaxies
• The Close AGN Reference Survey (CARS). A massive multi-phase outflow impacting the edge-on galaxy HE1353-1917
• The EDGE-CALIFA Survey: Central molecular gas depletion in AGN host galaxies -- a smoking gun for quenching?
• CO Multi-line Imaging of Nearby Galaxies (COMING). IX. ${}^{12}$CO($J$=2-1)/${}^{12}$CO($J$=1-0) line ratio on kiloparsec scales
• BASS XXXII: Studying the Nuclear Mm-wave Continuum Emission of AGNs with ALMA at Scales $\lesssim$ 100-200 pc
• Black hole accretion preferentially occurs in gas rich galaxies
• The rotation curves of flattened Sersic bulges
• Integral field spectroscopy of nearby QSOs II. The molecular gas content and condition for star formation
• An ALMA CO(2-1) Survey of Nearby Palomar-Green Quasars
• Black Hole Accretion Correlates with Star Formation Rate and Star Formation Efficiency in Nearby Luminous Type 1 Active Galaxies
• Physics of ULIRGs with MUSE and ALMA: PUMA IV. No tight relation between cold molecular outflow rates and AGN luminosities
• Reverberation mapping of narrow-line Seyfert 1 galaxy I Zwicky 1: black hole mass
• The Diverse Morphology, Stellar Population, and Black Hole Scaling Relations of the Host Galaxies of Nearby Quasars
• Physics of ULIRGs with MUSE and ALMA: The PUMA project I. Properties of the survey and first MUSE data results
• The Close AGN Reference Survey (CARS): Locating the [O III] wing component in luminous local Type 1 AGN
• Ionized Outflows in Nearby Quasars are Poorly Coupled to their Host Galaxies
• Enhanced Star Formation Efficiency in the Central Regions of Nearby Quasars Hosts
• Resolving the Interstellar Medium in Ultraluminous Infrared QSO Hosts with ALMA
• Compact Molecular Gas Distribution in Quasar Host Galaxies
• VALES VII: Molecular and ionized gas properties in pressure balanced interstellar medium of starburst galaxies at z ~ 0.15

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