The Binary Black Hole Model for Mrk 231 Bites the Dust

Mrk 231 is a nearby quasar with an unusually red near-UV-to-optical continuum, generally explained as heavy reddening by dust (e.g., Leighly et al. 2014). Yan et al. 2015 proposed that Mrk~231 is a milli-parsec black-hole binary with little intrinsic reddening. We show that if the observed FUV continuum is intrinsic, as assumed by Yan et al. 2015, it fails by a factor of about 100 in powering the observed strength of the near-infrared emission lines, and the thermal near and mid-infrared continuum. In contrast, the line and continuum strengths are typical for a reddened AGN spectral energy distribution. We find that the HeI*/Pbeta ratio is sensitive to the spectral energy distribution for a one-zone model. If this sensitivity is maintained in general broad-line region models, then this ratio may prove a useful diagnostic for heavily reddened quasars. Analysis of archival HST STIS and FOC data revealed evidence that the far-UV continuum emission is resolved on size scales of ~40 parsecs. The lack of broad absorption lines in the far-UV continuum might be explained if it were not coincident with the central engine. One possibility is that it is the central engine continuum reflected from the receding wind on the far side of the quasar.Comment: Consistent with the accepted ApJ pape

The Zero Point of Extinction Toward Baade's Window

We measure the zero point of the Stanek (1996) extinction map by comparing the observed (V-K) colors of 206 K giant stars with their intrinsic (V-K)_0 colors as derived from their H\beta indices. We find that the zero point of the Stanek map should be changed by \Delta A_V = -0.10 +/- 0.06 mag, obtaining as a bonus a three-fold reduction of the previous statistical error. The most direct way to test for systematic errors in this determination would be to conduct a parallel measurement based on the (V-K) colors of RR Lyraes (type ab).Comment: 10 pages, 1 figur

A Survey for EHB Stars in the Galactic Bulge

We present a progress report on an extensive survey to find and characterize all types of blue horizontal-branch stars in the nuclear bulge of the Galaxy. We have obtained wide, shallow imaging in UBV of ~12 square degrees in the bulge, with follow-up spectroscopy for radial velocities and metal abundance determinations. We have discovered a number of metal-rich blue HB stars, whose presence in the bulge is expected by the interpretation of the extragalactic ultraviolet excess. Very deep images have been obtained in UBV and SDSS u along the bulge minor axis, which reveal a significant number of EHB candidates fainter than B = 19, i.e., with the same absolute magnitudes as EHB stars in several globular clusters.Comment: To appear in "Extreme Horizontal Branch Stars and Related Objects", Astrophysics and Space Science, Kluwer Academic Publishers, proceedings of the meeting held in Keele, UK, June 16-20, 200

Detailed Surface Photometry of Dwarf Elliptical and Dwarf S0 Galaxies in the Virgo Cluster

We analyze new V-band images of 14 dwarf S0 galaxies and 10 dwarf elliptical galaxies in the Virgo Cluster, in combination with R-band images of 70 dwarf elliptical galaxies from an earlier paper. We compute the intensity-weighted mean ellipticity, the mean deviations from elliptical isophotes, and a newly defined parameter to measure isophotal twists. We also fit each major-axis profile to a power law Σ(a) α exp[-(a/as)n], where n is allowed to vary. Consistent with other studies of the Virgo dwarf ellipticals, we find that the profile shapes for the entire sample is strongly peaked near n=1 (exponential profiles) and that no galaxies have n=1/4 (de Vaucouleurs profile). The faintest galaxies all have nearly exponential profiles, while the brighter ones on average have n<1. The correlation between ellipticity and the boxy/disky parameter is similar to that of large elliptical galaxies, suggesting that dwarfs may also be divided into two groups with differing internal dynamics. The Virgo dEs also show a greater degree of isophotal twisting than more luminous elliptical galaxies. There does not seem to be any combination of parameters from the surface photometry that statistically correlates with the dE/dS0 designation: in particular, the dS0 galaxies do not, on average, have more pointed (disky) isophotes than the dEs

Discovery of a Remarkably Powerful Broad Absorption Line Quasar Outflow in SDSS J135246.37+423923.5

Broad absorption line (BAL) features in quasar spectra reveal an unambiguous signature of energetic outflows from central supermassive black holes, and thus BAL quasars are prime targets for investigating the potential process of luminous quasar feedback on galaxies. We analyzed the rest-UV spectrum of an "overlapping trough" iron low-ionization broad absorption line quasar (FeLoBAL) SDSS J135246.37+423923.5 using the novel spectral synthesis code SimBAL (Leighly et al. 2018) and discovered an extraordinarily fast and energetic BAL outflow. Our analysis revealed outflow velocities reaching $\sim -38000\rm \, km\, s^{-1}$ with a velocity width of $\sim 10000\rm \, km\, s^{-1}$ which is the largest FeLoBAL outflow velocity measured to date. The column density of the outflow gas is log$N_H\sim23.2\,[\rm cm^{-1}]$ with the log kinetic luminosity $\log L_{KE}\sim48.1$ [erg $\rm s^{-1}$] which exceeds the bolometric luminosity of the quasar and is energetic enough to effectively drive quasar feedback. The energy estimate for the outflow is far greater than the estimates from any BAL object previously reported. The object also shows "anomalous reddening" and a significant scattered component that we were able to model with SimBAL. We found the first definitive case for radiation filtering in an additional zero-velocity absorption component that required an absorbed continuum to produce the particular absorption lines observed (MgII, AlIII and AlII) without also producing the high ionization lines such as CIV