The Absolute Magnitude of the Sun in Several Filters

This paper presents a table with estimates of the absolute magnitude of the Sun and the conversions from $vegamag$ to the AB and ST systems for several wide-band filters used in ground and space-based observatories. These estimates use the dustless spectral energy distribution (SED) of Vega, calibrated absolutely using the SED of Sirius, to set the $vegamag$ zero-points and a composite spectrum of the Sun that coadds space-based observations from the ultra-violet to the near infrared with models of the Solar atmosphere. The uncertainty of the absolute magnitudes is estimated comparing the synthetic colors with photometric measurements of solar analogs and is found to be $\sim$ 0.02 magnitudes. Combined with the uncertainty of $\sim$ 2% in the calibration of the Vega SED, the errors of these absolute magnitudes are $\sim$ 3--4%. Using these SEDs, for the three of the most utilized filters in extragalactic work the estimated absolute magnitudes of the Sun are $M_B$ = 5.44, $M_V$ = 4.81 and $M_K$ = 3.27 mag in the $vegamag$ system and $M_B$ = 5.31, $M_V$ = 4.80 and $M_K$ = 5.08 mag in AB.Comment: 17 pages, 2 figures, accepted by ApJS. Composite solar spectrum available for download at http://mips.as.arizona.edu/~cnaw/sun.htm

Effects of the Environment on the Properties of Seyfert Galaxies

We identify 175 Seyfert galaxies from the Southern Sky Redshift Survey - SSRS2. We use the entire SSRS2 catalog to investigate the correlation between the presence of AGN with host environment. The AGN phenomenon is more strongly correlated with the internal host properties, than with the external environment. In particular, we find that Seyferts reside in more luminous galaxies, and are twice as frequent in barred galaxies and systems showing sign of advanced merger condition, when compared to a control sample.Comment: 4 pages, 3 figs, 1 tables, to appear in the proceedings of "The Interplay among Black Holes, Stars and ISM in Galactic Nuclei", IAU 222, eds. T. Storchi Bergmann, L.C. Ho, and H.R. Schmit

Mid-Infrared Selected Quasars I: Virial Black Hole Mass and Eddington Ratios

We provide a catalog of 391 mid-infrared-selected (MIR, 24$\mu$m) broad-emission-line (BEL, type 1) quasars in the 22 deg$^2$ SWIRE Lockman Hole field. This quasar sample is selected in the MIR from Spitzer MIPS with $S_{\rm 24} > 400\mu$Jy, jointly with an optical magnitude limit of r (AB) $<$ 22.5 for broad line identification. The catalog is based on MMT and SDSS spectroscopy to select BEL quasars, extends the SDSS coverage to fainter magnitudes and lower redshifts, and recovers a more complete quasar population. The MIR-selected quasar sample peaks at $z\sim$1.4, and recovers a significant and constant (20\%) fraction of extended objects with SDSS photometry across magnitudes, which was not included in the SDSS quasar survey dominated by point sources. This sample also recovers a significant population of $z 19.1$. We then investigate the continuum luminosity and line profiles of these MIR quasars, and estimate their virial black hole masses and the Eddington ratios. The SMBH mass shows evidence of downsizing, though the Eddington ratios remain constant at $1 < z < 4$. Compared to point sources in the same redshift range, extended sources at $z < 1$ show systematically lower Eddington ratios. The catalog and spectra are publicly available online.Comment: 72 pages, 27 figures, 16 tables; ApJ accepte

Properties of host galaxies of submillimeter sources as revealed by JWST Early Release Observations in SMACS J0723.3-7327

Using the 0.9--4.4~$\mu$m imaging data from the James Webb Space Telescope (JWST) Early Release Observation in the SMACS J0723.3-7327 galaxy cluster field, we discuss the properties of three submillimeter galaxies (SMGs) detected by the Atacama Large Millimeter Array. These sources are magnified by 1.4--2.1$\times$due to gravitational lensing. This is the first time that SMG host galaxies are resolved in the rest-frame near-infrared (NIR). One source was previous undetected by HST, while the remaining two are disk galaxies with S\'ersic indices of $\sim 0.9$ and star formation rates on or just below the star formation "main sequence". Their submillimeter emission originates from the inner parts of the hosts, suggesting that their dust contents are concentrated towards the center. The host half-light radii measured in the rest-frame NIR are $\sim$1.5$\times$ smaller than those measured in the rest-frame optical, consistent with a concentrated dust distribution. The more severe extinction that optical light suffers towards the center makes it seemingly less concentrated. Therefore, we expect that the optically-based determination of the stellar mass distribution within host galaxies could still be severely biased by dust. Interestingly, these two disk galaxies are dramatically different in their outer regions, with one being star forming and the other being quiescent. Upcoming JWST observations of statistically significant samples of SMGs will allow us to understand the correlation between the dusty star forming regions and their hosts.Comment: 11 pages, 7 figures, accepted by ApJ

The COS Absorption Survey of Baryon Harbors (CASBaH): Warm-hot Circumgalactic Gas Reservoirs Traced by Ne VIII Absorption

We survey the highly ionized circumgalactic media (CGM) of 29 blindly selected galaxies at 0.49 < z_(gal) < 1.44 based on high-S/N ultraviolet spectra of z > 1 QSOs and the galaxy database from the COS Absorption Survey of Baryon Harbors (CASBaH). We detect the Ne VIII doublet in nine of the galaxies, and for gas with N(Ne VIII) > 10^13.3 cm^-2 (> 10^13.5 cm^-2), we derive a Ne VIII covering fraction f_c = 75 +15/-25% (44 +22/-20%) within impact parameter (rho) < 200 kpc of M_* = 10^(9.5-11.5) Msol galaxies and f_c = 70 +16/-22% (f_c = 42 +20/-17%) within rho < 1.5 virial radii. We estimate the mass in Ne VIII-traced gas to be M_gas(Ne VIII) > 10^9.5 Msol (Z/Zsol)^-1, or 6-20% of the expected baryonic mass if the Ne VIII absorbers have solar metallicity. Ionizing Ne VII to Ne VIII requires 207 eV, and photons with this energy are scarce in the CGM. However, for the median halo mass and redshift of our sample, the virial temperature is close to the peak temperature for the Ne VIII ion, and the Ne VIII-bearing gas is plausibly collisionally ionized near this temperature. Moreover, we find that photoionized Ne VIII requires cool and low-density clouds that would be highly underpressured (by approximately two orders of magnitude) relative to the putative, ambient virialized medium, complicating scenarios where such clouds could survive. Thus, more complex (e.g., non-equilibrium) models may be required; this first statistical sample of Ne VIII absorber/galaxy systems will provide stringent constraints for future CGM studies.Comment: Published in ApJL, Volume 877, Issue 2, Article L2

AEGIS: Enhancement of Dust-enshrouded Star Formation in Close Galaxy Pairs and Merging Galaxies up to z ~ 1

Using data from the DEEP2 Galaxy Redshift Survey and HST/ACS imaging in the Extended Groth Strip, we select nearly 100 interacting galaxy systems including kinematic close pairs and morphologically identified merging galaxies. Spitzer MIPS 24 micron fluxes of these systems reflect the current dusty star formation activity, and at a fixed stellar mass (M_{*}) the median infrared luminosity (L_{IR}) among merging galaxies and close pairs of blue galaxies is twice (1.9 +/- 0.4) that of control pairs drawn from isolated blue galaxies. Enhancement declines with galaxy separation, being strongest in close pairs and mergers and weaker in wide pairs compared to the control sample. At z ~ 0.9, 7.1% +/- 4.3% of massive interacting galaxies (M_{*} > 2*10^{10} M_{solar}) are found to be ULIRGs, compared to 2.6% +/- 0.7% in the control sample. The large spread of IR luminosity to stellar mass ratio among interacting galaxies suggests that this enhancement may depend on the merger stage as well as other as yet unidentified factors (e.g., galaxy structure, mass ratio, orbital characteristics, presence of AGN or bar). The contribution of interacting systems to the total IR luminosity density is moderate (<= 36 %).Comment: 12 pages, 2 figures, 1 table, minor changes to match the proof version, accepted for publication in the ApJL AEGIS Special Issu