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Constrictive pericarditis is a rare cause of right-sided heart failure secondary to a stiff, non-compliant pericardium. Clinical presentation can vary considerably and requires a high suspicion for diagnosis. A 31-year-old male presented to the emergency department with complaints of abdominal distension. An abdominal ultrasound revealed large volume ascites; thus, it was initially suspected he had underlying cirrhosis. However, an echocardiogram revealed a diagnosis of constrictive pericarditis. It's important for clinicians to consider constrictive pericarditis in a patient presenting with unexplained right-sided heart failure.

BACKGROUND Treatment of congenitally corrected transposition of great arteries (cc-TGA) with anatomic repair strategy has been considered superior due to restoration of the morphologic left ventricle in the systemic circulation. However, data on long term outcomes are limited to single center reports and include small sample sizes. AIM To perform a systematic review and meta-analysis for observational studies reporting outcomes on anatomic repair for cc-TGA. METHODS MEDLINE and Scopus databases were queried using predefined criteria for reports published till December 31, 2017. Studies reporting anatomic repair of minimum 5 cc-TGA patients with at least a 2 year follow up were included. Meta-analysis was performed using Comprehensive meta-analysis v3.0 software. RESULTS Eight hundred and ninety-five patients underwent anatomic repair with a pooled follow-up of 5457.2 patient-years (PY). Pooled estimate for operative mortality was 8.3% [95% confidence interval (CI): 6.0%-11.4%]. 0.2% (CI: 0.1%-0.4%) patients required mechanical circulatory support postoperatively and 1.7% (CI: 1.1%-2.4%) developed post-operative atrioventricular block requiring a pacemaker. Patients surviving initial surgery had a transplant free survival of 92.5% (CI: 89.5%-95.4%) per 100 PY and a low rate of need for pacemaker (0.3/100 PY; CI: 0.1-0.4). 84.7% patients (CI: 79.6%-89.9%) were found to be in New York Heart Association (NYHA) functional class I or II after 100 PY follow up. Total re-intervention rate was 5.3 per 100 PY (CI: 3.8-6.8). CONCLUSION Operative mortality with anatomic repair strategy for cc-TGA is high. Despite that, transplant free survival after anatomic repair for cc-TGA patients is highly favorable. Majority of patients maintain NYHA I/II functional class. However, monitoring for burden of re-interventions specific for operation type is very essential.

Background: Identification of aortic and mitral valve opening and closure timing is crucial for assessment of left ventricle (LV) function, e.g. pressure-volume loops. This is particularly problematic when simultaneous imaging (e.g. echocardiography) is not available. We hypothesize that LV pressure and its time derivatives can detect valve opening and closure times. Our aim was to determine the aortic and mitral valve opening and closures using properties of the LV pressure waveform. Methods: For this pilot study, in 3 human participants in sinus rhythm, LV pressures were recorded with a high-fidelity catheter. Echocardiographic 2D-guided M-mode images were obtained across the aortic and mitral valves in the parasternal long axis view. The timing of aortic and mitral valve events was linked to the ECG tracing, using the peak of the ECG R wave as the reference point. For each participant, two consecutive heartbeats were selected and the first (dP/dt), second (d 2 P/dt 2 ), and third derivatives (d 3 P/dt 3 ) of LV pressure calculated. Local maxima and minima from these were compared with the valve timing from M-mode. Results: The maximum of dP/dt at the beginning of the systolic phase occurred consistently with the opening of the aortic valve. Local minimum and maximum d 2 P/dt 2 occurred at the closure of the aortic valve and pre-atrial contraction timing, respectively. The early diastolic minimum of d 3 P/dt 3 and early systolic maximum of d 3 P/dt 3 coincided with M-mode mitral valve opening and closure timing, respectively. There was a strong correlation between the valve events timing that was measured using these two methods (R 2 =0.98, p Conclusion: Aortic and mitral valve timing defined using LV pressure waveform agrees with valve opening/closure timing determined using echo M-mode as the gold standard. Determination of these valve timings is helpful for advanced analysis of LV mechanics when simultaneous echocardiography is not available.

Radio active galactic nuclei (RAGNs) are mainly found in dense structures (i.e., clusters/groups) at redshifts of z < 2 and are commonly used to detect protoclusters at higher redshift. Here, we attempt to study the host and environmental properties of two relatively faint (L 1.4 GHz ∼ 1025 W Hz−1) RAGNs in a known protocluster at z = 3.3 in the PCl J0227-0421 field, detected using the latest radio observation obtained as part of the Observations of Redshift Evolution in Large-Scale Environments (ORELSE) survey. Using new spectroscopic observations obtained from the Keck/Multi-Object Spectrometer for Infra-Red Exploration as part of the Charting Cluster Construction with the VIMOS Ultra-Deep Survey (VUDS) and ORELSE (C3VO) survey and previous spectroscopic data obtained as part of the VIMOS-Very Large Telescope Deep Survey and VUDS, we revise the three-dimensional overdensity field around this protocluster. The protocluster is embedded in a large-scale overdensity protostructure. This protostructure has an estimated total mass of ∼2.6 × 1015 M ⊙ and contains several overdensity peaks. Both RAGNs are hosted by very bright and massive galaxies, while their hosts show extreme differences in color, indicating that they are of different ages and are in different evolutionary stages. Furthermore, we find that they are not in the most locally dense parts of the protostructure, but are fairly close to the centers of their parent overdensity peaks. We propose a scenario where merging might have already happened in both cases, which lowered the local density of their surrounding area and boosted their stellar mass. This work is the first time that two RAGNs at low luminosity have been found and studied within a high-redshift protostructure.

Recent hydrodynamic simulations and observations of radio jets have shown that the surrounding environment has a large effect on their resulting morphology. To investigate this we use a sample of 50 Extended Radio Active Galactic Nuclei (ERAGN) detected in the Observations of Redshift Evolution in Large Scale Environments (ORELSE) survey. These sources are all successfully cross-identified to galaxies within a redshift range of $0.55 \leq z \leq 1.35$, either through spectroscopic redshifts or accurate photometric redshifts. We find that ERAGN are more compact in high-density environments than those in low-density environments at a significance level of 4.5$\sigma$. Among a series of internal properties under our scrutiny, only the radio power demonstrates a positive correlation with their spatial extent. After removing the possible radio power effect, the difference of size in low- and high-density environments persists. In the global environment analyses, the majority (86\%) of high-density ERAGN reside in the cluster/group environment. In addition, ERAGN in the cluster/group central regions are preferentially compact with a small scatter in size, compared to those in the cluster/group intermediate regions and fields. In conclusion, our data appear to support the interpretation that the dense intracluster gas in the central regions of galaxy clusters plays a major role in confining the spatial extent of radio jets.

A 47-year-old man with a history of d-transposition of the great arteries palliated with an atrial switch (Mustard) operation presented to our institution with progressive exertional dyspnea. Transthoracic echocardiography demonstrated pulmonary venous baffle stenosis, with a mean gradient of 17 mm

Introduction Anatomic repair of congenitally corrected transposition of great arteries (cc-TGA) has long held the promise of prevention of congestive heart failure by restoring the systemic ventricle function to the morphologic left ventricle. However data are limited and variable. We intended to perform a pooled analysis to try and delineate the outcomes after anatomic repair. Methods A comprehensive search of Medline and Scopus databases from inception through Dec 31, 2017 was conducted using predefined criteria. We included studies reporting anatomic repair of minimum 5 cc-TGA patients with a follow-up duration of 2 years or more. Meta-analysis was performed using Comprehensive meta-analysis v3.0 software. Random effects modelling was used because of observational nature of pooled data. Results In 21 eligible studies, 895 patients underwent anatomic repair with a pooled follow-up of 5457.2 person-years (PY). There was an even split between patients treated with the double switch operation and the atrial switch / ventricular re-routing operation. Pooled estimate for operative mortality was 8.3% (95% CI: 6.0-11.4%). 0.2% (CI: 0.1-0.4%) patients required ECMO/LVAD postoperatively and 1.7% (CI: 1.1-2.4%) developed post-operative AV block requiring a pacemaker. Patients surviving initial surgery had a transplant free survival of 92.5%(CI: 89.5-95.4%) per 100 PY and a low rate of need for pacemaker (0.5% / year; CI: 0.2-0.8%). 84.7% patients (CI: 79.6-89.9%) were found to be in NYHA functional class I or II after 100 PY follow up. Total re-intervention rate was 5.3% per year (CI: 3.8-6.8%). Incidence of baffle stenosis, AV valve dysfunction, neo-aortic insufficiency and LVOT obstruction were estimated at 1.1% (CI: 0.8-1.5%); 0.3% (CI: 0.2-0.5%); 0.5% (CI: 0.2-0.9%) and 0.4% (CI: 0.1-0.6%) per year. Rate of development of LV dysfunction was 1.7%/ year (CI: 1.0-2.4%). Conclusions Despite a relatively high operative mortality, our study provides favorable updated estimates for follow-up outcomes after anatomic repair for cc-TGA patients. The pooled data suggests need for active monitoring over the long term for important complications including heart block and worsening ventricular dysfunction despite majority of patients being in NYHA class I/II.

We present the first results from the deep and wide 5 GHz radio observations of the Great Observatories Origins Deep Survey (GOODS)-North ($\sigma=3.5 \; \mu Jy \; beam^{-1}$, synthesized beam size $\theta =$ 1.47 arcsec $\times$ 1.42 arcsec, and 52 sources over 109 arcmin$^{2}$) and GOODS-South ($\sigma=3.0 \; \mu Jy \; beam^{-1}$, $\theta=$0.98 arcsec $\times$ 0.45 arcsec, and 88 sources over 190 arcmin$^{2}$) fields using the Karl G. Jansky Very Large Array. We derive radio spectral indices {\alpha} between 1.4 and 5 GHz using the beam-matched images and show that the overall spectral index distribution is broad even when the measured noise and flux bias are considered. We also find a clustering of faint radio sources around $\alpha=0.8$, but only within $S_{5GHz} < 150 \; \mu Jy$. We demonstrate that the correct radio spectral index is important for deriving accurate rest frame radio power and analyzing the radio-FIR correlation, and adopting a single value of $\alpha=0.8$ leads to a significant scatter and a strong bias in the analysis of the radio-FIR correlation, resulting from the broad and asymmetric spectral index distribution. When characterized by specific star formation rates, the starburst population (58%) dominates the 5 GHz radio source population, and the quiescent galaxy population (30%) follows a distinct trend in spectral index distribution and the radio-FIR correlation. Lastly, we offer suggestions on sensitivity and angular resolution for future ultra-deep surveys designed to trace the cosmic history of star formation and AGN activity using radio continuum as a probe., Comment: 25 pages, 13 figures, Accepted for the publication in the Astrophysical Journal

We present a spectroscopically confirmed sample of Lyman alpha emitting galaxies (LAEs) at z ~ 4.5 in the Extended Chandra Deep Field South (ECDFS), which we combine with a sample of z ~ 4.5 LAEs from the Large Area Lyman Alpha (LALA) survey to build a unified Lya luminosity function (LF). We spectroscopically observed 64 candidate LAEs in the ECDFS, confirming 46 objects as z~4.5 LAEs. We did not detect significant flux from neither C_iv 1549\AA\ nor the He_ii 1640\AA\ emission in individual LAE spectra, even with a coadded spectrum. With the coadded line ratio of He_ii to Lya constraining the Population III star formation rate (SFR) to be 2$\sigma$ significance, and the product $L^*\Phi^*$ differs by a factor of >3. Similar LF differences have been used to infer evolution in the neutral gas fraction in the intergalactic medium at z>6, yet here the difference is likely due to cosmic variance, given that the two samples are from adjoining line-of-sight volumes. Combining our new sample of LAEs with those from previous LALA narrowband surveys at z = 4.5, we obtain one of the best measured Lya LFs to date of L* = 42.83 $\pm$ 0.06 and $\Phi^*$ = -3.48 $\pm$ 0.09. We compare our new LF to others from the literature to study the evolution of the Lya luminosity density at 0 < z < 7. We find tentative evidence for evolution in the product $L^* \Phi^*$, which approximately tracks the cosmic SFR density, but since field-to-field and survey-to-survey variations are in some cases as large as the possible evolution, some caution is needed in interpreting this trend.

We present $\simeq$0$.\!\!^{\prime\prime}4$-resolution extinction-independent distributions of star formation and dust in 11 star-forming galaxies (SFGs) at $z = 1.3-3.0$. These galaxies are selected from sensitive, blank-field surveys of the $2' \times 2'$ Hubble Ultra-Deep Field at $\lambda = 5$ cm and 1.3 mm using the Karl G. Jansky Very Large Array (VLA) and Atacama Large Millimeter/submillimeter Array (ALMA). They have star-formation rates (SFRs), stellar masses, and dust properties representative of massive main-sequence SFGs at $z \sim 2$. Morphological classification performed on spatially-resolved stellar mass maps indicates a mixture of disk and morphologically disturbed systems; half of the sample harbor X-ray active galactic nuclei (AGN), thereby representing a diversity of $z \sim 2$ SFGs undergoing vigorous mass assembly. We find that their intense star formation most frequently occurs at the location of stellar-mass concentration and extends over an area comparable to their stellar-mass distribution, with a median diameter of $4.2 \pm 1.8$ kpc. This provides direct evidence for galaxy-wide star formation in distant, blank-field-selected main-sequence SFGs. The typical galactic-average SFR surface density is 2.5 M$_{\odot}$yr$^{-1}$kpc$^{-2}$, sufficiently high to drive outflows. In X-ray-selected AGN where radio emission is enhanced over the level associated with star formation, the radio excess pinpoints the AGN, which are found to be co-spatial with star formation. The median extinction-independent size of main-sequence SFGs is two times larger than those of bright submillimeter galaxies whose SFRs are $3-8$ times larger, providing a constraint on the characteristic SFR ($\sim300$ M$_{\odot}$yr$^{-1}$) above which a significant population of more compact star-forming galaxies appears to emerge., Comment: 11 pages, 4 figures, accepted for publication in ApJ

We study the X-ray properties of 393 optically selected early-type galaxies (ETGs) over the redshift range of z≈ 0.0–1.2 in the Chandra Deep Fields (CDFs). To measure the average X-ray properties of the ETG population, we use X-ray stacking analyses with a subset of 158 passive ETGs (148 of which were individually undetected in X-ray). This ETG subset was constructed to span the redshift ranges of z= 0.1–1.2 in the ≈4 Ms CDF-South and ≈2 Ms CDF-North and z= 0.1–0.6 in the ≈250 ks Extended-CDF-South where the contribution from individually undetected active galactic nuclei (AGN) is expected to be negligible in our stacking. We find that 55 of the ETGs are detected individually in X-ray, and 12 of these galaxies have properties consistent with being passive hot-gas-dominated systems (i.e. systems not dominated by an X-ray bright AGN). On the basis of our analyses, we find little evolution in the mean 0.5–2 keV to B-band luminosity ratio (LX/LB∝ [1 +z]1.2) since z≈ 1.2, implying that some heating mechanism prevents the gas from cooling in these systems. We consider that feedback from radio-mode AGN activity could be responsible for heating the gas. We select radio AGN in the ETG population using their far-infrared/radio flux ratio. Our radio observations allow us to constrain the duty cycle history of radio AGN activity in our ETG sample. We estimate that if scaling relations between radio and mechanical power hold out to z≈ 1.2 for the ETG population being studied here, the average mechanical power from AGN activity is a factor of ≈1.4–2.6 times larger than the average radiative cooling power from hot gas over the redshift range z≈ 0–1.2. The excess of inferred AGN mechanical power from these ETGs is consistent with that found in the local Universe for similar types of galaxies.

We explore the application of XMM Newton Optical Monitor (XMM-OM) ultraviolet (UV) data to study galaxy evolution. Our sample is constructed as the intersection of all Abell clusters with z < 0.05 and having archival XMM-OM data in either the UVM2 or UVW1 filters, plus optical and UV photometry from the Sloan Digital Sky Survey and GALEX, respectively. The 11 resulting clusters include 726 galaxies with measured redshifts, 520 of which have redshifts placing them within their parent Abell clusters. We develop procedures for manipulating the XMM-OM images and measuring galaxy photometry from them, and we confirm our results via comparison with published catalogs. Color-magnitude diagrams (CMDs) constructed using the XMM-OM data along with SDSS optical data show promise for evolutionary studies, with good separation between red and blue sequences and real variation in the width of the red sequence that is likely indicative of differences in star formation history. This is particularly true for UVW1 data, as the relative abundance of data collected using this filter and its depth make it an attractive choice. Available tools that use stellar synthesis libraries to fit the UV and optical photometric data may also be used, thereby better describing star formation history within the past billion years and providing estimates of total stellar mass that include contributions from young stars. Finally, color-color diagrams that include XMM-OM UV data appear useful to the photometric identification of both extragalactic and stellar sources.

Measuring star formation rates (SFRs) in high-z galaxies with their rest-frame ultraviolet (UV) continuum can be uncertain because of dust obscuration. Prior studies had used the submillimeter emission at 850 um to determine the intrinsic SFRs of rest-frame UV selected galaxies, but the results suffered from the low sensitivity and poor resolution (~15''). Here, we use ultradeep Very Large Array 1.4 GHz images with ~1''-2'' resolutions to measure the intrinsic SFRs. We perform stacking analyses in the radio images centered on ~3500 Lyman break galaxies (LBGs) at z~4 in the Great Observatories Origins Deep Survey-North and South fields selected with Hubble Space Telescope/Advanced Camera for Surveys data. The stacked radio flux is very low, 0.08+/-0.15 uJy, implying a mean SFR of 6+/-11 M/yr. This is comparable to the uncorrected mean UV SFRs of 5 M/yr, implying that the z~4 LBGs have little dust extinction. The low SFR and dust extinction support the previous results that z~4 LBGs are in general not submillimeter galaxies. We further show that there is no statistically significant excess of dust-hidden star-forming components within ~22 kpc from the LBGs., 6 pages, 3 figures, and 2 tables. Accepted to the Astrophysical Journal (ApJ)

Transcatheter (TC) closure of secundum atrial septal defects (ASD) has made rapid strides and is the modality of choice for clinicians. We investigated temporal trends and in-hospital outcomes of transcatheter and surgical(S) ASD closure in adult patients using the National Inpatient Sample database

We present the optical and infrared identifications of the 266 radio sources detected at 20 cm with the Very Large Array in the Chandra Deep Field South (Kellermann et al. 2008). Using deep i-band Advanced Camera for Surveys, R-band Wide Field Imager, K-band SOFI/NTT, K-band ISAAC/VLT and Spitzer imaging data, we are able to find reliable counterparts for 254 (~95%) VLA sources. Twelve radio sources remain unidentified and three of them are ``empty fields''. Using literature and our own data we are able to assign redshifts to 186 (~70%) radio sources: 108 are spectroscopic redshifts and 78 reliable photometric redshifts. Based on the rest frame colors and morphological distributions of the host galaxies we find evidences for a change in the submillijansky radio source population: a) above ~ 0.08 mJy early-type galaxies are dominating; b) at flux densities below ~0.08 mJy, starburst galaxies become dominant., To appear in ApJS, 50 pages with 15 figures, an ASCII varsion of Table 3 and a version with higher resolution figures are available at http://taltos.pha.jhu.edu/~nmiller/vlaecdfs_main.html

We describe the HST ACS Coma Cluster Treasury survey, a deep two-passband imaging survey of one of the nearest rich clusters of galaxies, the Coma Cluster (Abell 1656). The survey was designed to cover an area of 740 arcmin2 in regions of different density of both galaxies and intergalactic medium within the cluster. The ACS failure of 2007 January 27 leaves the survey 28% complete, with 21 ACS pointings (230 arcmin2) complete, and partial data for a further four pointings (44 arcmin2). The predicted survey depth for 10 σ detections for optimal photometry of point sources is g'=27.6 in the F475W filter and IC=26.8 mag in F814 (AB magnitudes). Initial simulations with artificially injected point sources show 90% recovered at magnitude limits of g'=27.55 and IC=26.65. For extended sources, the predicted 10 σ limits for a 1 arcsec2 region are g'=25.8 mag arcsec-2 and IC=25.0 mag arcsec-2. We highlight several motivating science goals of the survey, including study of the faint end of the cluster galaxy luminosity function, structural parameters of dwarf galaxies, stellar populations and their effect on colors and color gradients, evolution of morphological components in a dense environment, the nature of ultracompact dwarf galaxies, and globular cluster populations of cluster galaxies of a range of luminosities and types. This survey will also provide a local rich cluster benchmark for various well-known global scaling relations and explore new relations pertaining to the nuclear properties of galaxies. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. These observations are associated with program GO10861.

We have spectroscopically identified 77 new members of the Cygnus A cluster, bringing the total to 118 galaxies consistent with cluster membership. We use these data combined with the results from X-rays to deduce a dynamical model for the system. The data are consistent with a cluster-cluster merger viewed at a projection angle of 30-45 degrees, 0.2-0.6 Gyr prior to core passage. We estimate the richness of the combined cluster system at Abell richness class 2 or greater, suggesting the merger of two richness class 1 clusters., Comment: 41 pages, 7 figures, 2 tables, accepted AJ

We report the detection of radio emission coincident with the ultraluminous X-ray source (ULX) in Holmberg II. The radio emission is diffuse and resolved, covering an area ~60 by 40 pc in extent and well-matched to the recently discovered HeII nebula surrounding the X-ray source. Comparison of the radio and optical properties of this extended radio emission argue against its association with either an HII region or supernova remnant. This is additional evidence that this ULX is not powered by a stellar-mass object whose emission is relativistically beamed towards the observer, and thus is either a super-Eddington source or intermediate mass black hole as suggested by optical observations. Implications of this result to future and existing radio studies of ULXs are discussed.

We present 371 galaxy velocities in the field of the very rich cluster Abell 2125 (z~0.25). These were determined using optical spectroscopy collected over several years from both the WIYN 3.5m telescope and NOAO Mayall 4m telescope. Prior studies at a variety of wavelengths (radio, optical, and X-ray) have indicated that A2125 is a likely cluster-cluster merger, a scenario which we are able to test using our large velocity database. We identified 224 cluster galaxies, which were subjected to a broad range of statistical tests using both positional and velocity information to evaluate the cluster dynamics and substructure. The tests confirmed the presence of substructures within the Abell 2125 system at high significance, demonstrating that A2125 is a complex dynamical system. Comparison of the test results with existing simulations strengthens the merger hypothesis, and provides clues about the merger geometry and stage. The merger model for the system can reconcile A2125's low X-ray temperature and luminosity with its apparently high richness, and might also explain A2125's high fraction of active galaxies identified in prior radio and optical studies.

We report 0.8–2.5 μm spectrophotometry of CI Aquilae at eight epochs between 2000 May 9 and 2001 June 2 UT, corresponding to approximately 3 and 391 days after peak brightness. Near peak brightness, the spectra showed emission lines that were characteristic of a low-excitation, nitrogen-rich shell. Within a few weeks, the spectra began to show higher excitation/ionization emission lines indicative of a harder illuminating source: the neutral metal lines faded, leaving only lines of H I, He I, and He II and the emerging coronal lines. A month after peak brightness, the [Ca VIII] coronal line at 2.3205 μm appeared and persisted until the last of our observations, on day +391. From the O I line ratios, we deduced a reddening of EB-V = 1.5 ± 0.1 and a visual extinction of AV = 4.6 ± 0.2. Along with the rate of decline from the light curve (t2), we derived a distance of 2.6 ± 1.3 kpc. The frequently observed unidentified novae lines were present in CI Aquilae along with a potentially new member of the group at 2.425 ± 0.002 μm.

Deep VLA 1.4 GHz radio continuum imaging of Abell 2255 is presented. This cluster is among the better nearby candidates for rich cluster-cluster merger systems, with evidence including an elongated X-ray morphology, the presence of a radio halo, and substructure present in its galaxy distribution. Our radio observations reach an rms sensitivity of ~40 uJy/beam, enabling us to detect (at 5 sigma) star formation rates as low as 1.4 M(sun)/year from the center of the cluster out to a radial distance of 3 Mpc. The radio data are complemented by optical imaging and a large spectroscopic database, allowing us to separate all galaxies with M_R < -20 into cluster members and foreground/background galaxies. The spectra are also used to associate the galaxies' radio emission with either star formation or AGN. We compare the resulting cluster radio galaxy population with those of nineteen other nearby Abell clusters, and find strong evidence for an increase in the frequency of radio galaxies in Abell 2255. This increase is seen in two separate types of galaxies: powerful radio AGN and optically-faint star forming galaxies. The optical spectra of the latter often indicate current or recent starbursts, and these galaxies appear to be distributed along an axis perpendicular to the probable merger axis. We assess these factors in light of models of galaxy evolution, and suggest that the cluster-cluster merger is responsible for triggering galaxy activity in Abell 2255., 21 pages, plus 13 JPEG figures; to appear in the Astronomical Journal

We present new M and L-dwarfs confirmed through follow-up of 2MASS color-selected objects with the CorMASS near-infrared spectrograph (R ˜ 300) on the Palomar 60-inch telescope as part of a continuing follow-up survey. Most of the objects are bright (Ks < 13).

Multifiber optical spectroscopy has been performed on galaxies in the vicinity of strong, nearby radio galaxies. These radio galaxies were selected from the 3CR and B2 catalogs based on their exclusion from the Abell catalog, which is puzzling given the hypothesis that an external medium is required to confine the radio plasma of such galaxies. Velocities derived from the spectra were used to confirm the existence of groups and poor clusters in the fields of most of the radio galaxies. We find that all radio galaxies with classical FR I morphologies prove to reside in clusters, whereas the other radio galaxies often appear to be recent galaxy-galaxy mergers in regions of low galaxy density. These findings confirm the earlier result that the existence of extended X-ray emission combined with a statistical excess of neighboring galaxies can be used to identify poor clusters associated with radio galaxies., 45 pages including tables and figures, to appear in the Astronomical Journal

We present results from a new optical/UV/X-ray monitoring campaign of the luminous Seyfert galaxy Fairall 9 using the Swift satellite. Using the UV-Optical Telescope (UVOT) on Swift, we find correlated optical/UV variability on all time scales ranging from the sampling time (4-days) to the length of the campaign (2.5 months). In one noteworthy event, the UW2-band flux dips by 20% in 4-days, and then recovers equally quickly; this event is not seen in either the optical or the X-ray bands. We argue that this event provides further evidence that a significant fraction of the UV-emission must be driven by irradiation/reprocessing of emission from the central disk. We also use an archival XMM-Newton observation to examine shorter time scale UV/X-ray variability. We find very rapid ( $8\times10^4$ K) region. The possible association with X-ray microflares suggests that we may be seeing the UV signatures of direct X-ray flare heating of the innermost disk., Accepted for publication in ApJ

We present our very recent results on the sub-mJy radio source populations at 1.4 GHz based on the Extended Chandra Deep Field South VLA survey, which reaches ~ 30 {\mu}Jy, with details on their number counts, evolution, and luminosity functions. The sub-mJy radio sky turns out to be a complex mix of star-forming galaxies and radio-quiet AGN evolving at a similar, strong rate and declining radio-loud AGN. While the well-known flattening of the radio number counts below 1 mJy is mostly due to star-forming galaxies, these sources and AGN make up an approximately equal fraction of the sub-mJy sky. Our results shed also light on a fifty-year-old issue, namely radio emission from radio-quiet AGN, and suggest that it is closely related to star formation, at least at z ~ 1.5 - 2. The implications of our findings for future, deeper radio surveys, including those with the Square Kilometre Array, are also discussed. One of the main messages, especially to non-radio astronomers, is that radio surveys are reaching such faint limits that, while previously they were mainly useful for radio quasars and radio galaxies, they are now detecting mostly star-forming galaxies and radio-quiet AGN, i.e., the bulk of the extragalactic sources studied in the infrared, optical, and X-ray bands., Comment: 7 pages, three figures, invited talk at IAU S304, Multiwavelength AGN Surveys and Studies, Yerevan, Armenia, Oct. 7-11, 2013, to appear in the proceedings

Using the 1.4 GHz Australia Telescope Large Area Survey (ATLAS), supplemented with the 1.4 GHz Very Large Array images, we undertook a search for bent-tailed (BT) radio galaxies in the Chandra Deep Field-South (CDFS). Here we present a catalog of 56 detections, which include 45 bent-tailed sources, four diffuse low-surface-brightness objects (one relic, two halos, and one unclassified object), and a further seven complex, multi-component sources. We report BT sources with rest-frame powers in the range $10^{22} \leq$ $\textrm{P}_{1.4 \textrm{ GHz}} \leq 10^{26}$ W Hz$^{-1}$, redshifts up to 2 and linear extents from tens of kpc up to about one Mpc. This is the first systematic study of such sources down to such low powers and high redshifts and demonstrates the complementary nature of searches in deep, limited area surveys as compared to shallower, large surveys. Of the sources presented here one is the most distant bent-tailed source yet detected at a redshift of 2.1688. Two of the sources are found to be associated with known clusters: a wide-angle tail source in Abell 3141 and a putative radio relic which appears at the infall region between the galaxy group MZ 00108 and the galaxy cluster AMPCC 40. Further observations are required to confirm the relic detection, which if successful would demonstrate this to be the least powerful relic yet seen with $\textrm{P}_{1.4 \textrm{ GHz}} = 9 \times 10^{22}$ W Hz$^{-1}$. Using these data we predict future 1.4 GHz all-sky surveys with a resolution of $\sim$ 10 arcseconds and sensitivity of 10 $\mu$Jy will detect of the order of 560,000 extended low-surface-brightness radio sources of which 440,000 will have a bent-tailed morphology., Comment: 12 pages, 5 figures, accepted for publication in AJ

We report on the use of the NRAO VLA Sky Survey (NVSS) to identify radio galaxie s in eighteen nearby Abell clusters. The listings extend from the cores of the clusters out to radii of 3 Mpc, which corresponds to 1.5 Abell radii and approximately four orders of magnitude in galaxy density. To create a truly useful catalog, we have collected optical spectra for nearly all of the galaxies lacking public velocity measurements. Consequently, we are able to discriminate between those radio galaxies seen in projection on the cluster and those which are in actuality cluster members. The resulting catalog consists of 329 cluster radio galaxies plus 138 galaxies deemed foreground/background objects, and new velocity measurements are reported for 273 of these radio galaxies. The motivation for the catalog is the study of galaxy evolution in the cluster environment. The radio luminosity function (RLF) is a powerful tool in the identification of active galaxies, as it is dominated by star-forming galaxies at intermediate luminosities and active galactic nuclei (AGN) at higher luminosities. The flux limit of the NVSS allows us to identify AGN and star- forming galaxies down to star formation rates (SFR) less than 1 solar mass per year. This sensitivity, coupled with the all-sky nature of the NVSS, allows us to produce a catalog of considerable depth and breadth. In addition to these data, we report detected infrared fluxes and upper limits obtained from IRAS data. It is hoped that this database will prove useful in a number of potential studies of the effect of environment on galaxy evolution., 53 pages (AASTeX v5.0), plus 3 figures. To appear in the Astrophysical Journal Supplement Series

Radio source counts constrain galaxy populations and evolution, as well as the global star formation history. However, there is considerable disagreement among the published 1.4-GHz source counts below 100 microJy. Here we present a statistical method for estimating the microJy and even sub-microJy source count using new deep wide-band 3-GHz data in the Lockman Hole from the Karl G. Jansky Very Large Array (VLA). We analyzed the confusion amplitude distribution P(D), which provides a fresh approach in the form of a more robust model, with a comprehensive error analysis. We tested this method on a large-scale simulation, incorporating clustering and finite source sizes. We discuss in detail our statistical methods for fitting using Monte Carlo Markov chains, handling correlations, and systematic errors from the use of wide-band radio interferometric data. We demonstrated that the source count can be constrained down to 50 nJy, a factor of 20 below the rms confusion. We found the differential source count near 10 microJy to have a slope of -1.7, decreasing to about -1.4 at fainter flux densities. At 3GHz the rms confusion in an 8arcsec FWHM beam is ~ 1.2 microJy/beam, and a radio background temperature ~ 14mK. Our counts are broadly consistent with published evolutionary models. With these results we were also able to constrain the peak of the Euclidean normalized differential source count of any possible new radio populations that would contribute to the cosmic radio background down to 50 nJy., 21 pages, 18 figures, 7 tables, Accepted for publication in MNRAS

We present results from deep X-ray stacking of >4000 high redshift galaxies from z~1 to 8 using the 4 Ms Chandra Deep Field South (CDF-S) data, the deepest X-ray survey of the extragalactic sky to date. The galaxy samples were selected using the Lyman break technique based primarily on recent HST ACS and WFC3 observations. Based on such high specific star formation rates (sSFRs): log SFR/M* > -8.7, we expect that the observed properties of these LBGs are dominated by young stellar populations. The X-ray emission in LBGs, eliminating individually detected X-ray sources (potential AGN), is expected to be powered by X-ray binaries and hot gas. We find, for the first time, evidence of evolution in the X-ray/SFR relation. Based on X-ray stacking analyses for z5, we use our upper limits from 5, Comment: 16 pages, 9 figures. Accepted for publication in ApJ

We study a sample of 883 sources detected in a deep Very Large Array survey at 1.4 GHz in the Extended Chandra Deep Field South. The paper focuses on the identification of their optical and infrared (IR) counterparts. We use a likelihood ratio technique that is particularly useful when dealing with deep optical images to minimize the number of spurious associations. We find a reliable counterpart for 95% of our radio sources. Most of the counterparts (74%) are detected at optical wavelengths, but there is a significant fraction (21%) only detectable in the IR. Combining newly acquired optical spectra with data from the literature we are able to assign a redshift to 81% of the identified radio sources (37% spectroscopic). We also investigate the X-ray properties of the radio sources using the Chandra 4 Ms and 250 ks observations. In particular, we use a stacking technique to derive the average properties of radio objects undetected in the Chandra images. The results of our analysis are collected in a new catalog containing the position of the optical/IR counterpart, the redshift information and the X-ray fluxes. It is the deepest multi-wavelength catalog of radio sources, which will be used for future study of this galaxy population., 18 pages, 11 figures, accepted for publication in ApJS, Table 3 and 5 are available in their entirety in the ancillary data

We used the Karl G. Jansky Very Large Array (VLA) to image one primary beam area at 3 GHz with 8 arcsec FWHM resolution and 1.0 microJy/beam rms noise near the pointing center. The P(D) distribution from the central 10 arcmin of this confusion-limited image constrains the count of discrete sources in the 1 < S(microJy/beam) < 10 range. At this level the brightness-weighted differential count S^2 n(S) is converging rapidly, as predicted by evolutionary models in which the faintest radio sources are star-forming galaxies; and ~96$% of the background originating in galaxies has been resolved into discrete sources. About 63% of the radio background is produced by AGNs, and the remaining 37% comes from star-forming galaxies that obey the far-infrared (FIR) / radio correlation and account for most of the FIR background at lambda = 160 microns. Our new data confirm that radio sources powered by AGNs and star formation evolve at about the same rate, a result consistent with AGN feedback and the rough correlation of black hole and bulge stellar masses. The confusion at centimeter wavelengths is low enough that neither the planned SKA nor its pathfinder ASKAP EMU survey should be confusion limited, and the ultimate source detection limit imposed by "natural" confusion is < 0.01 microJy at 1.4 GHz. If discrete sources dominate the bright extragalactic background reported by ARCADE2 at 3.3 GHz, they cannot be located in or near galaxies and most are < 0.03 microJy at 1.4 GHz., 28 pages including 16 figures. ApJ accepted for publication