Robert W. Kastenmeier: Copyright Legislator Par Excellence

The legacy of Robert W. Kastenmeier, former Chairman of the House Judiciary Subcommittee on Courts, Intellectual Property and the Administration of Justice, is discussed. Kastenmeier deserves praise for his leadership on patent and copyright laws

CLASS Survey Description: Coronal Line Needles in the SDSS Haystack

Coronal lines are a powerful, yet poorly understood, tool to identify and characterize Active Galactic Nuclei (AGNs). There have been few large scale surveys of coronal lines in the general galaxy population in the literature so far. Using a novel pre-selection technique with a flux-to-RMS ratio $F$, followed by Markov-Chain Monte Carlo (MCMC) fitting, we searched for the full suite of 20 coronal lines in the optical spectra of almost 1 million galaxies from the Sloan Digital Sky Survey (SDSS) Data Release 8. We present a catalog of the emission line parameters for the resulting 258 galaxies with detections. The Coronal Line Activity Spectroscopic Survey (CLASS) includes line properties, host galaxy properties, and selection criteria for all galaxies in which at least one line is detected. This comprehensive study reveals that a significant fraction of coronal line activity is missed in past surveys based on a more limited set of coronal lines; $\sim$60% of our sample do not display the more widely surveyed [Fe X] $\lambda$6374. In addition, we discover a strong correlation between coronal line and WISE W2 luminosities, suggesting that the mid-infrared flux can be used to predict coronal line fluxes. For each line we also provide a confidence level that the line is present, generated by a novel neural network, trained on fully simulated data. We find that after training the network to detect individual lines using 100,000 simulated spectra, we achieve an overall true positive rate of 75.49% and a false positive rate of only 3.96%.Comment: 27 pages, 16 figures, 4 table

The Messy Nature of Fiber Spectra: Star-Quasar Pairs Masquerading as Dual Type 1 AGNs

Theoretical studies predict that the most significant growth of supermassive black holes occurs in late-stage mergers, coinciding with the manifestation of dual active galactic nuclei (AGNs), and both major and minor mergers are expected to be important for dual AGN growth. In fact, dual AGNs in minor mergers should be signposts for efficient minor merger-induced SMBH growth for both the more and less massive progenitor. We identified two candidate dual AGNs residing in apparent minor mergers with mass ratios of $\sim$1:7 and $\sim$1:30. SDSS fiber spectra show broad and narrow emission lines in the primary nuclei of each merger while only a narrow [O III] emission line and a broad and prominent H$\alpha$/[N II] complex is observed in the secondary nuclei. The FWHMs of the broad H$\alpha$ lines in the primary and secondary nuclei are inconsistent in each merger, suggesting that each nucleus in each merger hosts a Type 1 AGN. However, spatially-resolved LBT optical spectroscopy reveal rest-frame stellar absorption features, indicating the secondary sources are foreground stars and that the previously detected broad lines are likely the result of fiber spillover effects induced by the atmospheric seeing at the time of the SDSS observations. This study demonstrates for the first time that optical spectroscopic searches for Type 1/Type 1 pairs similarly suffer from fiber spillover effects as has been observed previously for Seyfert 2 dual AGN candidates. The presence of foreground stars may not have been clear if an instrument with more limited wavelength range or limited sensitivity had been used.Comment: 15 pages including appendix and references, 6 figures, 1 table. Accepted for publication in Ap

Laser experiments to simulate supernova remnants

An experiment using a large laser facility to simulate young supernova remnants (SNRs) is discussed. By analogy to the SNR, the laboratory system includes dense matter that explodes, expansion and cooling to produce energetic, flowing plasma, and the production of shock waves in lower-density surrounding matter. The scaling to SNRs in general and to SN1987A in particular is reviewed. The methods and results of x-ray radiography, by which the system in diagnosed, are discussed. The data show that the hohlraum used to provide the energy for explosion does so in two ways—first, through its radiation pulse, and second, through an additional impulse that is attributed to stagnation pressure. Attempts to model these dynamics are discussed. © 2000 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69889/2/PHPAEN-7-5-2142-1.pd

Nuclear Activity in the Low Metallicity Dwarf Galaxy SDSS J0944-0038: A Glimpse into the Primordial Universe

Local low metallicity dwarf galaxies are relics of the early universe and hold clues into the origins of supermassive black holes (SMBHs). In recent work, coronal lines have been used to unveil a population of candidate accreting black holes in dwarf galaxies with gas phase metallicities and stellar masses well below the host galaxies of any previously known AGNs. Using MUSE/VLT observations, we report the detection of [Fe X] $\lambda$6374 coronal line emission and a broad H$\alpha$ line in the nucleus of SDSS J094401.87$-$003832.1, a nearby ($z=0.0049$) metal poor dwarf galaxy at least fifty times less massive than the LMC. The [Fe X] $\lambda$6374 emission is compact and centered on the brightest nuclear source, with a spatial extent of $\approx$100 pc. The [Fe X] luminosity is $\approx 10^{37}$ erg s$^{-1}$, within the range seen in previously identified AGNs in the dwarf galaxy population. This line has never been observed in gas ionized by hot stars. While it can be produced in supernova ejecta, the [Fe X] flux from SDSS J094401.87$-$003832.1 has persisted over the ~19 year time period between the SDSS and MUSE observations, ruling out supernovae as the origin for the emission. The FWHM of the broad component of the H$\alpha$ line is $446 \pm 17$ km s$^{-1}$ and its luminosity is $\approx 1.5\times10^{38}$ erg s$^{-1}$, lower than the broad line luminosities of previously identified low mass broad line AGNs. These observations, together with previously reported multi-wavelength observations, can most plausibly be explained by the presence of an accreting intermediate mass black hole in a primordial galaxy analog. However, we cannot rule out the possibility that current stellar population models of metal poor stars significantly under-predict the stellar ionizing photon flux, and that metal poor stars can produce an extreme ionizing spectrum similar to that produced by AGNs.Comment: 12 pages, 5 figures, 1 table, submitted to ApJL. Comments welcom