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We measure velocity offsets in the |$\rm{Na {}\rm {\small I}}$| λλ5890, 5896 (⁠|$\rm{Na {}\rm {\small D}}$|⁠) interstellar medium absorption lines to track how neutral galactic winds change as their host galaxies evolve. Our sample of ∼80 000 SDSS spectra at 0.010 < z < 0.325 includes starburst, post-starburst, and quiescent galaxies, forming an evolutionary sequence of declining star formation rate (SFR). We detect bulk flows across this sequence, mostly at higher host stellar masses (log(M */M⊙)) > 10). Along this sequence, the fraction of outflows decreases (76 ± 2 per cent to 65 ± 4 per cent to a 3σ upper limit of 34 per cent), and the mean velocity offset changes from outflowing to inflowing (−84.6 ± 5.9 to −71.6 ± 11.4 to |$76.6\pm 2.3\, \rm km s^{-1}$|⁠). Even within the post-starburst sample, wind speed decreases with time elapsed since the starburst ended. These results reveal that outflows diminish as galaxies age. For post-starbursts, there is evidence for an AGN contribution, especially to the speediest outflows: (1) SFR declines faster in time than outflow velocity, a decoupling arguing against massive stellar feedback; (2) of the few outflows strong enough to escape the interstellar medium (9/105), three of the four hosts with measured emission lines are Seyfert galaxies. For discy starburst galaxies, however, the trends suggest flows out of the stellar disc plane (with outflow 1/2-opening angle > 45°) instead of from the nucleus: the wind velocity decreases as the disc becomes more edge-on, and the outflow fraction, constant at |$\sim 90~{{\ \rm per\ cent}}$| for disc inclinations i < 45°, steadily decreases from |$\sim 90~{{\ \rm per\ cent}}$| to 20 per cent for i > 45°. [ABSTRACT FROM AUTHOR]

We predict late-time optical/UV emission from tidal disruption events (TDEs) from our slim accretion disc model (Wen et al. 2020) and explore the impact of the black hole mass M •, black hole spin a •, and accretion disc size. We use these synthetic spectra to successfully fit the multiband Swift observations of ASASSN-14li at >350 d, setting only the host galaxy extinction and outer disc radius as free parameters and employing the M •, a •, disc inclination, and disc accretion rates derived from fitting 10 epochs of ASASSN-14li's X-ray spectra with the slim disc. To address the nature of the early -time optical/UV emission, we consider two models: shock dissipation and reprocessing. We find that (1) the predicted late-time optical/UV colour (e.g. u − w 2) is insensitive to black hole and disc parameters unless the disc spreads quickly; (2) a starburst galaxy extinction model is required to fit the data, consistent with ASASSN-14li's post-starburst host; (3) surprisingly, the outer disc radius is ≈2 × the tidal radius and ∼constant at late times, showing that viscous spreading is slow or non-existent; (4) the shock model can be self-consistent if M • ≲ 106.75 M⊙, i.e. on the low end of ASASSN-14li's M • range (106.5–7.1 M⊙; 1σ CL); larger black hole masses require disruption of an unrealistically massive progenitor star; (5) the gas mass needed for reprocessing, whether by a quasi-static or an outflowing layer, can be <0.5 M⊙, consistent with a (plausible) disruption of a solar-mass star. [ABSTRACT FROM AUTHOR]

Even though galactic winds are common in galaxies with starbursts or active galactic nuclei (AGN), the role of such gas flows in galaxy evolution remains uncertain. Here we examine how winds vary along a likely evolutionary sequence connecting starburst to post-starburst to quiescent galaxies. To detect the interstellar medium and measure its bulk flows, we examine the residual Na D absorption line doublet after the stellar contribution has been removed from each galaxy's spectrum. We discover that outflows diminish along this sequence, i.e., as star formation ends. We then focus on the wind behavior within the post-starburst sample, for which we have measured the time elapsed since the starburst ended (post-burst age) via detailed modeling of their star formation histories (French et al.2018). Even within our post-starburst sample, the fraction of galaxies with significant winds and the average wind velocities decrease with post-burst age after controlling for stellar mass. [ABSTRACT FROM AUTHOR]

Tidal disruption events (TDEs) are highly energetic phenomena that occur when a star is tidally disrupted by the central massive black hole in a galaxy. Fitting the observed X-ray spectra of TDEs with a first-principles, general-relativistic slim-disk model for the emission from the inner accretion disk can constrain the black hole mass M • and dimensionless spin a •. Multiepoch spectra can break degeneracies in parameter estimation, particularly when they include a period of super-Eddington mass accretion. Even one observed super-Eddington epoch can be useful. Constraints on { M •, a •} improve as a power law with the number of spectral counts; the power-law index is higher for a higher mass accretion rate. These results are supported by the successful modeling of real spectra in the nearby (0.0206 ≤ z ≤ 0.145) TDEs ASASSN-14li, 3XMM J150052.0+015452, and 3XMM J215022.4–055108, which were observed over multiple epochs with >1 ks exposure times. Guided by these results, we create an updated and expanded TDE catalog from the Open TDE compilation. We then explore the XMM-Newton and Chandra archives to identify 37 TDE candidates with promising spectra for constraining { M •, a •} with slim-disk model fits. At least seven TDEs are likely associated with intermediate-mass black holes. Three of the 24 TDEs with multiepoch UV/optical photometry from Swift have late-time observations that allow their light curves to be compared directly to model predictions from the X-ray spectral fits. Existing X-ray spectra for other TDEs can be augmented with future optical/UV data. Ultimately, our new TDE catalog will reveal the { M •, a •} distributions traced by TDEs, thereby discriminating among black hole growth scenarios and providing insights on general relativity and dark matter particle candidates. The new TDE catalog is here: https://github.com/aarongoldtooth/Census-of-TDE-and-Archival-X-Ray-UV-Data/blob/main/Full%20New%20TDE%20Catalog%20(Published).tsv, and the codes used to construct it are here: https://github.com/aarongoldtooth/Census-of-TDE-and-Archival-X-Ray-UV-Data. [ABSTRACT FROM AUTHOR]

We present an analysis of the intracluster light (ICL) in the Frontier Field Cluster MACS J1149.5+2223 (z  = 0.544), which combines new and archival Hubble WFC3/IR imaging to provide continuous radial coverage out to 2.8 Mpc from the brightest cluster galaxy (BCG). Employing careful treatment of potential systematic biases and using data at the largest radii to determine the background sky level, we reconstruct the surface brightness profile out to a radius of 2 Mpc. This radius is the largest to which the ICL has been measured for an individual cluster. Within this radius, we measure a total luminosity of 1.5 × 1013 L⊙ for the BCG plus ICL. From the profile and its logarithmic slope, we identify the transition from the BCG to ICL at r ∼ 70 kpc. Remarkably, we also detect an apparent inflection in the profile centred in the 1.2–1.7 Mpc (0.37–0.52 r 200 m ) radial bin, a signature of an infall caustic in the stellar distribution. Based upon the shape and strength of the feature, we interpret it as potentially being at the splashback radius, although the radius is smaller than theoretical predictions. If this is the splashback radius, then it is the first such detection in the ICL and the first detection of the splashback radius for an individual cluster. Similar analyses should be possible with the other Frontier Field clusters, and eventually with clusters observed by the Euclid and Roman missions. [ABSTRACT FROM AUTHOR]

In strong gravitational lens systems, the light bending is usually dominated by one main galaxy, but may be affected by other mass along the line of sight (LOS). Shear and convergence can be used to approximate the contributions from less significant perturbers (e.g. those that are projected far from the lens or have a small mass), but higher order effects need to be included for objects that are closer or more massive. We develop a framework for multiplane lensing that can handle an arbitrary combination of tidal planes treated with shear and convergence and planes treated exactly (i.e. including higher order terms). This framework addresses all of the traditional lensing observables including image positions, fluxes, and time delays to facilitate lens modelling that includes the non-linear effects due to mass along the LOS. It balances accuracy (accounting for higher order terms when necessary) with efficiency (compressing all other LOS effects into a set of matrices that can be calculated up front and cached for lens modelling). We identify a generalized multiplane mass sheet degeneracy, in which the effective shear and convergence are sums over the lensing planes with specific, redshift-dependent weighting factors. [ABSTRACT FROM PUBLISHER]

We present a study of the hot gas and stellar content of five optically selected poor galaxy clusters, including a full accounting of the contribution from intracluster light (ICL) and a combined hot gas and hydrostatic X-ray mass analysis with XMM–Newton observations. We find weighted mean stellar (including ICL), gas and total baryon mass fractions within r500 of 0.026 ± 0.003, 0.070 ± 0.005 and 0.096 ± 0.006, respectively, at a corresponding weighted mean M500 of (1.08+ 0.21− 0.18) × 1014 M⊙. Even when accounting for the intracluster stars, four out of five clusters show evidence for a substantial baryon deficit within r500, with baryon fractions (fb) between 50 ± 6 and 59 ± 8 per cent of the universal mean level (i.e. Ωb/Ωm), the remaining cluster having fb = 75±11 per cent. For the three clusters where we can trace the hot halo to r500 we find no evidence for a steepening of the gas density profile in the outskirts with respect to a power law, as seen in more massive clusters. We find that in all cases, the X-ray mass measurements are larger than those originally published on the basis of the galaxy velocity dispersion (σ) and an assumed σ-M500 relation, by a factor of 1.7–5.7. Despite these increased masses, the stellar fractions (in the range 0.016–0.034, within r500) remain consistent with the trend with mass published by Gonzalez et al., from which our sample is drawn. [ABSTRACT FROM AUTHOR]

Using a sample of 57 377 star-forming galaxies drawn from the Sloan Digital Sky Survey, we study the relationship between gas-phase oxygen abundance and environment in the local Universe. We find that there is a strong relationship between metallicity and environment such that more metal-rich galaxies favour regions of higher overdensity. Furthermore, this metallicity–density relation is comparable in strength to the colour–density relation along the blue cloud. After removing the mean dependence of environment on colour and luminosity, we find a weak, though significant, residual trend between metallicity and environment which is largely driven by galaxies in high-density regions, such as groups and clusters. We discuss the potential source of this relationship between metallicity and local galaxy density in the context of feedback models, with special attention paid to quantifying the impact of environment on the scatter in the mass–metallicity relation. We find that environment is a non-negligible source of scatter in this fundamental relation, with ≳15 per cent of the measured scatter correlated with environment. [ABSTRACT FROM AUTHOR]

While the baryon fraction in galaxy groups and clusters may be expected to reflect the universal value, observations of cluster baryon fractions have generally fallen short of this expectation and indicated a possible correlation with cluster mass. We present a new determination of the total baryon budget in nearby galaxy groups and clusters that includes the contributions from stars in galaxies, intracluster stars, and the intracluster medium. We find that the baryon mass fraction within r500 is independent of system mass and lower than the WMAP value. We conclude however that the present shortfall provides no compelling evidence for additional missing baryons, since it may arise due to a theoretically predicted deficit of baryons within r500 and systematic uncertainties associated with the mass determinations. With the addition of the ICL to the stellar mass in galaxies, the increase in X-ray gas mass fraction with increasing total mass is entirely accounted for by a decrease in the total stellar mass fraction, supporting the argument that the behavior of both the stellar and X-ray gas components is dominated by a decrease in star formation efficiency in more massive environments. Within just the stellar component, the fraction of the total stellar luminosity in the central, giant brightest cluster galaxy (BCG) and ICL (hereafter the BCG+ICL component) decreases as velocity dispersion (σ) increases, suggesting that ICL may grow less efficiently in higher mass environments. The identification of low mass groups with large BCG+ICL components also demonstrates that the massive cluster environment is not required to form intracluster stars. These proceedings are a condensed version of the work presented in Gonzalez, Zaritsky & Zabludoff (2007), and we refer the reader to that paper for a more complete discussion. [ABSTRACT FROM PUBLISHER]

We present the analysis of the spectroscopic and photometric catalogues of 11 X-ray luminous clusters at 0.07 < z < 0.16 from the Las Campanas/Anglo–Australian Telescope Rich Cluster Survey. Our spectroscopic data set consists of over 1600 galaxy cluster members, of which two-thirds are outside r200. These spectra allow us to assign cluster membership using a detailed mass model and expand on our previous work on the cluster colour–magnitude relation (CMR) where membership was inferred statistically. We confirm that the modal colours of galaxies on the CMR become progressively bluer with increasing radius and with decreasing local galaxy density d( B− R)/dlog (Σ) =−0.062 ± 0.009. Interpreted as an age effect, we hypothesize that these trends in galaxy colour should be reflected in mean Hδ equivalent width. We confirm that passive galaxies in the cluster increase in Hδ line strength as . Therefore, those galaxies in the cluster outskirts may have younger luminosity-weighted stellar populations; up to 3 Gyr younger than those in the cluster centre assuming d( B− R)/d t= 0.03 mag per Gyr. A variation of star formation rate, as measured by [O ii]λ3727 Å, with increasing local density of the environment is discernible and is shown to be in broad agreement with previous studies from the 2dF Galaxy Redshift Survey and the Sloan Digital Sky Survey. We divide our spectra into a variety of types based upon the MORPHs classification scheme. We find that clusters at z∼ 0.1 are less active than their higher-redshift analogues: about 60 per cent of the cluster galaxy population is non-star forming, with a further 20 per cent in the post-starburst class and 20 per cent in the currently active class, demonstrating that evolution is visible within the past 2–3 Gyr. We also investigate unusual populations of blue and very red non-star forming galaxies and we suggest that the former are likely to be the progenitors of galaxies which will lie on the CMR, while the colours of the latter possibly reflect dust reddening. We show that the cluster galaxies at large radii consist of both backsplash ones and those that are infalling to the cluster for the first time. We make a comparison to the field population at z∼ 0.1 and examine the broad differences between the two populations. Individually, the clusters show significant variation in their galaxy populations which we suggest reflects their recent infall histories. [ABSTRACT FROM AUTHOR]

We used a sample of 20 poor groups of galaxies to study the low mass tail of the relationships among the X-ray temperature T, the X-ray luminosity Lx and the optical velocity dispersion σ. We obtained redshifts for the fainter members of these groups. We find that X-ray bright groups have more members and higher velocity dispersions on average. Using the fainter group members and Monte Carlo tests, we define the number of group members required to calculate a robust velocity dispersion. There is a tendency to underestimate the group velocity dispersion for samples of fewer than ∼ 10 members that introduces systematic errors in the slope of the relationships among Lx, T, and σ. A comparison with the data of Ponman and Mahdavi shows that our improved velocity dispersions provide better constraints on the relationship between the kinematics of the hot gas and galaxies in these common environments. [ABSTRACT FROM AUTHOR]

We present the first modern systematic study of local brightest cluster galaxy (BCG) profiles that extends to radii beyond 200h-1 kpc. Measuring the surface brightness profiles of BCGs out to large radii is critical for understanding the processes driving their formation. The form of the profiles yields information about the current dynamical state, constrains the accretion history of these galaxies, and places limits on any radially symmetric component of intracluster light. The observational challenges associated with CCD photometry at low surface brightness levels have until now precluded such an analysis for a statistical sample of BCGs. Utilizing drift-scan data and new techniques that we have developed, we extend upon previous work by modelling the profiles for a sample of 31 clusters at z≃ that span a wide range in mass and dynamical state. We find that the BCGs in our sample generally are best fit using two-component models consisting of inner and outer Sersic profiles. In this proceeding we present the preliminary results of our analysis and discuss implications for current models of BCG formation. [ABSTRACT FROM AUTHOR]

Focuses on the Las Campanas Observatory and Anglo-Australian Telescope Rich Cluster Survey in Australia. Collection of charge-coupled device imaging of galaxy samples; Use of samples for spectroscopic survey of clusters; Comparison of LARCS catalogue with 2dF Galaxy Redshift Survey catalogue.