A high Eddington-ratio, true Seyfert 2 galaxy candidate: implications for broad-line-region models

A bright, soft X-ray source was detected on 2010 July 14 during an XMM--Newton slew at a position consistent with the galaxy GSN 069 (z=0.018). Previous ROSAT observations failed to detect the source and imply that GSN 069 is now >240 times brighter than it was in 1994 in the soft X-ray band. We report here results from a ~1 yr monitoring with Swift and XMM-Newton, as well as from optical spectroscopy. GSN 069 is an unabsorbed, ultra-soft source in X-rays, with no flux detected above ~1 keV. The soft X-rays exhibit significant variability down to timescales of hundreds of seconds. The UV-to-X-ray spectrum of GSN 069 is consistent with a pure accretion disc model which implies an Eddington ratio of ~0.5 and a black hole mass of ~ 1.2 million solar masses. A new optical spectrum, obtained ~3.5 months after the XMM-Newton slew detection, is consistent with earlier spectra and lacks any broad line component, classifying the source as a Seyfert 2 galaxy. The lack of cold X-ray absorption and the short timescale variability in the soft X-rays rule out a standard Seyfert 2 interpretation of the X-ray data. We discuss our results within the framework of two possible scenarios for the broad-line-region (BLR) in AGN, namely the two-phase model (cold BLR clouds in pressure equilibrium with a hotter medium), and models in which the BLR is part of an outflow, or disc-wind. Finally, we point out that GSN 069 may be a member of a population of super-soft AGN whose SED is completely dominated by accretion disc emission, as it is the case in some black hole X-ray binary transients during their outburst evolution. The disc emission for a typical AGN with larger black hole mass than GSN 069 does not enters the soft X-ray band, so that GSN 069-like objects would likely be missed by current X-ray surveys, or mis-classified as Compton-thick candidates. (ABRIDGED)Comment: Accepted for publication in MNRA

X-ray studies of HESS J1837--069 with Suzaku and ASCA: a VHE gamma-ray source originated from the pulsar wind nebula

We present the ASCA and Suzaku studies of the TeV source HESS J1837--069, which has not been identified in other wave-lengths. We confirm the presence of two X-ray sources in the Suzaku XIS image, AX J1838.0--0655 and AX J1837.3--0652, near both ends of the elongated TeV emission region. The XIS spectra of the two sources are reproduced by an absorbed power-law model, whose parameters are all consistent with those determined by the ASCA data. Recently, 70.5 ms X-ray pulsation has been detected with RXTE in the sky region including HESS J1837--069 (2008, ApJ, 681, 515). Using the ASCA GIS data which has both timing and imaging capabilities, we identified the pulsation source as AX J1838.0--0655. The pulse periods determined by ASCA and Suzaku, and that reported with RXTE indicate steady spin-down at $\dot{P} = 4.917(4) \times 10^{-14}$ s s$^{-1}$. These results suggest that AX J1838.0--0655 is an intrinsically stable source, and presumably a pulsar wind nebula (PWN). We discuss the possibility that AX J1838.0--0655 is associated with HESS J1837--069 and the VHE gamma-ray emission is originated from the PWN.Comment: 9 pages, 7 figures, accepted for publication in PASJ, revised figure

The Hamburg/ESO R-process Enhanced Star survey (HERES) IV. Detailed abundance analysis and age dating of the strongly r-process enhanced stars CS 29491-069 and HE 1219-0312

We report on a detailed abundance analysis of two strongly r-process enhanced, very metal-poor stars newly discovered in the HERES project, CS 29491-069 ([Fe/H]=-2.51, [r/Fe]=+1.1) and HE 1219-0312 ([Fe/H]=-2.96, [r/Fe]=+1.5). The analysis is based on high-quality VLT/UVES spectra and MARCS model atmospheres. We detect lines of 15 heavy elements in the spectrum of CS 29491-069, and 18 in HE 1219-0312; in both cases including the Th II 4019 {\AA} line. The heavy-element abundance patterns of these two stars are mostly well-matched to scaled solar residual abundances not formed by the s-process. We also compare the observed pattern with recent high-entropy wind (HEW) calculations, which assume core-collapse supernovae of massive stars as the astrophysical environment for the r-process, and find good agreement for most lanthanides. The abundance ratios of the lighter elements strontium, yttrium, and zirconium, which are presumably not formed by the main r-process, are reproduced well by the model. Radioactive dating for CS 29491-069 with the observed thorium and rare-earth element abundance pairs results in an average age of 9.5 Gyr, when based on solar r-process residuals, and 17.6 Gyr, when using HEW model predictions. Chronometry seems to fail in the case of HE 1219-0312, resulting in a negative age due to its high thorium abundance. HE 1219-0312 could therefore exhibit an overabundance of the heaviest elements, which is sometimes called an "actinide boost"

[4 + 2] Cycloadditions of diphenylketene with a highly substituted 1,3-diene

Diphenylketene (2) undergoes [4 + 2] cycloadditions with the s-cis fixed diene (1) to give the dihydropyran (3) and the cyclohexenone (4)

MS-069: Papers of John W. Vannorsdall

The Papers of John W. Vannorsdall consist correspondence and issues proposals from the late 1960’s and early 1970’s from the Office of the Chaplain at Gettysburg College. The papers also include papers pertaining to the Chapel and the Student Christian Association during the same time period. Special Collections and College Archives Finding Aids are discovery tools used to describe and provide access to our holdings. Finding aids include historical and biographical information about each collection in addition to inventories of their content. More information about our collections can be found on our website http://www.gettysburg.edu/special_collections/collections/.https://cupola.gettysburg.edu/findingaidsall/1063/thumbnail.jp

A Metadata-Enabled Scientific Discourse Platform

Scientific papers and scientific conferences are still, despite the emergence of several new dissemination technologies, the de-facto standard in which scientific knowledge is consumed and discussed. While there is no shortage of services and platforms that aid this process (e.g. scholarly search engines, websites, blogs, conference management programs), a widely accepted platform used to capture and enrich the interactions of research community has yet to appear. As such, we aim to create new ways for the members and interested people working in research communities to interact; before, during and after their conferences. Furthermore, to serve as a base to these interactions, we want not only to obtain, format and manage a body of legacy and new papers related to this community but also to aggregate several useful information and services to the environment of a discourse platform

New Mexico Lobo, Volume 069, No 59, 2/9/1966

New Mexico Lobo, Volume 069, No 59, 2/9/1966https://digitalrepository.unm.edu/daily_lobo_1966/1009/thumbnail.jp

New Mexico Lobo, Volume 069, No 18, 10/18/1965

New Mexico Lobo, Volume 069, No 18, 10/18/1965https://digitalrepository.unm.edu/daily_lobo_1965/1086/thumbnail.jp