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We present optical integral field spectroscopy for five narrow-line Seyfert 1 (NLS1) galaxies, probing their host galaxies at scales. Emission lines from the active galactic nucleus (AGN) and the large-scale host galaxy are analyzed separately, based on an AGN–host decomposition technique. The host galaxy gas kinematics indicates large-scale gas rotation in all five sources. At the probed scales of , the host galaxy gas is found to be predominantly ionized by star formation without any evidence of a strong AGN contribution. None of the five objects shows specific star formation rates (SFRs) exceeding the main sequence of low-redshift star-forming galaxies. The specific SFRs for MCG-05-01-013 and WPVS 007 are roughly consistent with the main sequence, while ESO 399-IG20, MS 22549-3712, and TON S180 show lower specific SFRs, intermediate to the main sequence and the red quiescent galaxies. The host galaxy metallicities, derived for the two sources with sufficient data quality (ESO 399-IG20 and MCG-05-01-013), indicate central oxygen abundances just below the low-redshift mass–metallicity relation. Based on this initial case study, we outline a comparison of AGN and host galaxy parameters as a starting point for future extended NLS1 studies with similar methods. [ABSTRACT FROM AUTHOR]

We present results of integral field spectroscopy of Balmer-dominated shocks in the LMC supernova remnant (SNR) N103B, carried out using the Wide Field Integral Spectrograph (WiFeS ) on the 2.3 m telescope at the Siding Spring Observatory in Australia. Existing X-ray studies of N103B have indicated an SN Ia origin. Radiative shock emission from clumpy material surrounding the SNR may result from interaction of the forward shock with relic stellar wind material, possibly implicating a thermonuclear explosion in a single-degenerate binary system. The recently discovered Balmer-dominated shocks mark the impact of the forward shock with low density, partially neutral CSM gas, and form a partial shell encircling clumps of material exhibiting radiative shocks. The WiFeS spectra of N103B reveal broad Hα emission having a width as high as 2350 km s−1 along the northern rim, and both Hα and Hβ broad profiles having widths around 1300 km s−1 along the southern rim. Fits to the Hα line profiles indicate that in addition to the usual broad and narrow emission components, a third component of intermediate width exists in these Balmer-dominated shocks, ranging from around 125 km s−1 up to 225 km s−1 in width. This is consistent with predictions of recent Balmer-dominated shock models, which predict that an intermediate-width component will be generated in a fast neutral precursor. We derive a Sedov age of approximately 685 ± 20 years for N103B from the Balmer-dominated spectra, consistent with the young age of 380–860 years estimated from light echo studies. [ABSTRACT FROM AUTHOR]

We present a simplified model of active galactic nucleus (AGN) continuum emission designed for photoionization modeling. The new model oxaf reproduces the diversity of spectral shapes that arise in physically based models. We identify and explain degeneracies in the effects of AGN parameters on model spectral shapes, with a focus on the complete degeneracy between the black hole mass and AGN luminosity. Our reparametrized model oxaf removes these degeneracies and accepts three parameters that directly describe the output spectral shape: the energy of the peak of the accretion disk emission , the photon power-law index of the non-thermal emission Γ, and the proportion of the total flux that is emitted in the non-thermal component . The parameter is presented as a function of the black hole mass, AGN luminosity, and “coronal radius” of the optxagnf model upon which oxaf is based. We show that the soft X-ray excess does not significantly affect photoionization modeling predictions of strong emission lines in Seyfert narrow-line regions. Despite its simplicity, oxaf accounts for opacity effects where the accretion disk is ionized because it inherits the “color correction” of optxagnf. We use a grid of mappings photoionization models with oxaf ionizing spectra to demonstrate how predicted emission-line ratios on standard optical diagnostic diagrams are sensitive to each of the three oxaf parameters. The oxaf code is publicly available in the Astrophysics Source Code Library. [ABSTRACT FROM AUTHOR]

We present CO(1–0) maps of 12 warm H2-selected Hickson Compact Groups (HCGs), covering 14 individually imaged warm H2 bright galaxies, with the Combined Array for Research in Millimeter Astronomy. We found a variety of molecular gas distributions within the HCGs, including regularly rotating disks, bars, rings, tidal tails, and possibly nuclear outflows, though the molecular gas morphologies are more consistent with spirals and early-type galaxies than mergers and interacting systems. Our CO-imaged HCG galaxies, when plotted on the Kennicutt–Schmidt relation, shows star formation (SF) suppression of distributed bimodally, with five objects exhibiting suppressions of ≳ 10 and depletion timescales ≳10 Gyr. This SF inefficiency is also seen in the efficiency per freefall time of Krumholz et al. We investigate the gas-to-dust ratios of these galaxies to determine if an incorrect LCO–M(H2) conversion caused the apparent suppression and find that HCGs have normal gas-to-dust ratios. It is likely that the cause of the apparent suppression in these objects is associated with shocks injecting turbulence into the molecular gas, supported by the fact that the required turbulent injection luminosity is consistent with the bright H2 luminosity reported by Cluver et al. Galaxies with high SF suppression ( ≳ 10) also appear to be those in the most advanced stages of transition across both optical and infrared color space. This supports the idea that at least some galaxies in HCGs are transitioning objects, where a disruption of the existing molecular gas in the system suppresses SF by inhibiting the molecular gas from collapsing and forming stars efficiently. These observations, combined with recent work on poststarburst galaxies with molecular reservoirs, indicates that galaxies do not need to expel their molecular reservoirs prior to quenching SF and transitioning from blue spirals to red early-type galaxies. This may imply that SF quenching can occur without the need to starve a galaxy of cold gas first. [ABSTRACT FROM AUTHOR]