Warm molecular and ionized gas kinematics in the Type-2 quasar J0945+1737

Abstract

We analyze Near-Infrared Integral Field Spectrograph (NIFS) observations of the type-2 quasar (QSO2) SDSS J094521.33+173753.2 to investigate its warm molecular and ionized gas kinematics. This QSO2 has a bolometric luminosity of 10${}^{45.7}$ erg s${}^{-1}$ and a redshift of z = 0.128. The K-band spectra provided by NIFS cover a range of 1.99-2.40 $\hat{I}¼$m where low-ionization (Pa$\hat{I}\pm$ and Br$\hat{I}´$), high ionization ([S XI]$\hat{I}»$1.920 $\hat{I}¼$m and [Si~VI]$\hat{I}»$1.963 $\hat{I}¼$m) and warm molecular lines (from H${}_2$ 1-0S(5) to 1-0S(1)) are detected, allowing us to study the multi-phase gas kinematics. Our analysis reveals gas in ordinary rotation in all the emission lines detected and also outflowing gas in the case of the low- and high-ionization emission lines. In the case of the nuclear spectrum, which corresponds to a circular aperture of 0.3\arcsec~(686 pc) in diameter, the warm molecular lines can be characterized using a single Gaussian component of full width at half maximum (FWHM)= 350-400 km s${}^{-1}$, while Pa$\hat{I}\pm$, Br$\hat{I}´$, and [Si~VI] are best fitted with two blue-shifted Gaussian components of FWHM$\sim$800 and 1700 km s${}^{-1}$, in addition to a narrow component of $\sim$300 km s${}^{-1}$. We interpret the blue-shifted broad components as outflowing gas, which reaches the highest velocities, of up to $-$840 km s${}^{-1}$, in the south-east direction (PA$\sim$125${}^{\circ }$), extending up to a distance of $\sim$3.4 kpc from the nucleus. The ionized outflow has a maximum mass outflow rate of ${\dot{\text{M}}}_{\text{out, max}}$=42-51 M${}_{\odot }$ yr${}^{-1}$, and its kinetic power represents 0.1$\%$ of the quasar bolometric luminosity.

24 pages, 20 figures and 5 tables. Accepted for publication in A&A