Symbiotic star surveys have traditionally relied almost exclusively on low resolution optical spectroscopy. However, we can obtain a more reliable estimate of their total Galactic population by using all available signatures of the symbiotic phenomenon. Here we report the discovery of a hard X-ray source, 4PBC J0642.9+5528, in the Swift hard X-ray all-sky survey, and identify it with a poorly studied red giant, SU Lyn, using pointed Swift observations and ground-based optical spectroscopy. The X-ray spectrum, the optical to UV spectrum, and the rapid UV variability of SU Lyn are all consistent with our interpretation that it is a symbiotic star containing an accreting white dwarf. The symbiotic nature of SU Lyn went unnoticed until now, because it does not exhibit emission lines strong enough to be obvious in low resolution spectra. We argue that symbiotic stars without shell-burning have weak emission lines, and that the current lists of symbiotic stars are biased in favor of shell-burning systems. We conclude that the true population of symbiotic stars has been underestimated, potentially by a large factor.

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.

We present the first J-band spectrum of Mrk 231, which reveals a large He I*λ10830 broad absorption line with a profile similar to that of the wellknown Na I broad absorption line. Combining this spectrum with optical and UV spectra from the literature, we show that the unusual reddening noted by Veilleux et al. (2013) is explained by a reddening curve like those previously used to explain low values of total-to-selective extinction in SNe Ia. The nuclear starburst may be the origin and location of the dust. Spatially-resolved emission in the broad absorption line trough suggests nearly full coverage of the continuum emission region. The broad absorption lines reveal higher velocities in the He I* lines (produced in the quasar-photoionized H II region) compared with the Na I and Ca II lines (produced in the corresponding partially-ionized zone).Cloudy simulations show that a density increase is required between the H II and partially-ionized zones to produce ionic column densities consistent with the optical and IR absorption line measurements and limits, and that the absorber lies ∼ 100 pc from the central engine. These results suggest that the He I* lines are produced in an ordinary quasar BAL wind that impacts upon, compresses, and accelerates the nuclear starburst's dusty effluent (feedback in action), and the Ca II and Na I lines are produced in this dusty accelerated gas. This unusual circumstance explains the rarity of Na I absorption lines; without the compression along our line of sight, Mrk 231 would appear as an ordinary FeLoBAL.

We show for the first time that FBQS J1151+3822 is an iron low-ionization broad absorption line quasar (FeLoBAL QSO), the second-brightest and secondclosest known example of this class. He I* and Fe II together act as an effective analytical tool, allowing us to obtain useful kinematic constraints from photoionization models of the outflow without needing to assume any particular acceleration model. The main outflow's log ionization parameter is −1.5, the log hydrogen density (cm −3 ) 5.5-8, the log hydrogen column density (cm −2 ) 21.7-21.9, the absorption radius 7.2-127 pc, and the kinetic luminosity 0.16%-4.5% of the bolometric luminosity. We obtain line-of-sight covering fractions of ∼ 0.25 for strong Fe II, ∼ 0.5 for He I*, and ∼ 0.6 for Mg II. Narrower and shallower absorption lines from weaker Fe II and Mn II with outflow velocity ∼ 3400 km s −1 have appeared between 2005 and 2011, suggesting that dense cores may have condensed inside the main outflow. Consideration of the literature might suggest that the FBQS J1151+3822 outflow is a member of a rare and distinct subclass of FeLoBALs with high densities and correspondingly small absorption radii. We find, however, that such outflows are not necessarily a distinct subclass, and that their apparent rarity could be a symptom of selection bias in studies using density-sensitive lines.

We present results from a ≈100 ks Chandra observation of the 2QZ Cluster 1004+00 structure at z = 2.23 (hereafter, 2QZ Clus). 2QZ Clus was originally identified as an overdensity of four optically-selected QSOs at z = 2.23 within a 15 × 15 arcmin 2 region. Narrow-band imaging in the near-IR (within the K band) revealed that the structure contains an additional overdensity of 22 z = 2.23 Hα-emitting galaxies (HAEs), resulting in 23 unique z = 2.23 HAEs/QSOs (22 within the Chandra field of view). Our Chandra observations reveal that 3 HAEs in addition to the 4 QSOs harbor powerfully accreting supermassive black holes (SMBHs), with 2-10 keV luminosities of ≈(8-60) ×10 43 ergs s −1 and X-ray spectral slopes consistent with unobscured AGN. Using a large comparison sample of 210 z = 2.23 HAEs in the Chandra-COSMOS field (C-COSMOS), we find suggestive evidence that the AGN fraction increases with local HAE galaxy density. The 2QZ Clus HAEs reside in a moderately overdense environment (a factor of ≈2 times over the field), and after excluding optically-selected QSOs, we find the AGN fraction is a factor of ≈3.5 +3.8 −2.2 times higher than C-COSMOS HAEs in similar environments. Using stacking analyses of the Chandra data and Herschel SPIRE observations at 250µm, we respectively estimate mean SMBH accretion rates (Ṁ BH ) and star-formation rates (SFRs) for the 2QZ Clus and C-COSMOS samples. We find that the mean 2QZ Clus HAE stacked X-ray luminosity is QSO-like (L 2−10 keV ≈ [6-10] ×10 43 ergs s −1 ), and the impliedṀ BH /SFR ≈ (1.6-3.2) ×10 −3 is broadly consistent with the local M BH /M ⋆ relation and z ≈ 2 X-ray selected AGN. In contrast, the C-COSMOS HAEs are on average an order of magnitude less X-ray luminous and haveṀ BH /SFR ≈ (0.2-0.4) ×10 −3 , somewhat lower than the local M BH /M ⋆ relation, but comparable to that found for z ≈ 1-2 star-forming galaxies with similar mean X-ray luminosities. We estimate that a periodic QSO phase with duty cycle ≈2-8% would be sufficient to bring star-forming galaxies onto the local M BH /M ⋆ relation. This duty cycle is broadly consistent with the observed C-COSMOS HAE AGN fraction (≈0.4-2.3%) for powerful AGN with L X > ∼ 10 44 ergs s −1 . Future observations of 2QZ Clus will be needed to identify key factors responsible for driving the mutual growth of the SMBHs and galaxies.