GBT Radio Monitoring of Magnetars

Magnetars are very exotic objects that are related to neutron stars and pulsars. A neutron star is formed when a massive star undergoes a supernova explosion. The super-dense core that is left after such an explosion is a neutron star. It is approximately 10 miles in diameter, yet weighs more than our Sun. We can observe some of those neutron stars as pulsars. Pulsars are highly magnetic, fast spinning neutron stars that emit beams of radio waves from their magnetic poles. Their high magnetic field and spin period are due to the conservation of magnetic flux and momentum during formation. Pulsar spin periods range from 1ms-8s and tend to slow down rapidly. That is another indication of a strong magnetic field, as magnetic braking causes the pulsar to spin-down rapidly. Magnetars are a type of a neutron star with extremely high magnetic fields of 1015-1014 G, which makes these stars the most magnetic objects known. These fields are thought to be generated by a dynamo action during the magnetar’s formation (Duncan and Thompson 1992). This is known as a magnetar model. The decay of the magnetic field creates powerful X-ray or gamma-ray emission. However, this magnetic field decays rather fast which makes the magnetar’s detectable lifespan short. Some of the known magnetars have poorly understood radio emission. Our group was motivated to better study the correlation between X-ray and radio activity of magnetars via a radio monitoring project. We are regularly observing eight magnetar sources that are visible with the 100-m Green Bank Telescope (GBT) located in Green Bank, WV. Our program is the first major effort to monitor these sources on a regular basis and complements other existing observing programs of southern objects at the Parkes radio telescope (Burgay et al. 2009; Camilo et al. 2009) as well as the high-energy monitoring projects with the Swift gamma-ray observatory and XMM X-ray observatory

Evidence for an interaction between the Galactic Center clouds M0.10-0.08 and M0.11-0.11

We present high-resolution (~2-3"; ~0.1 pc) radio observations of the Galactic center cloud M0.10-0.08 using the Very Large Array at K and Ka band (~25 and 36 GHz). The M0.10-0.08 cloud is located in a complex environment near the Galactic center Radio Arc and the adjacent M0.11-0.11 molecular cloud. From our data, M0.10-0.08 appears to be a compact molecular cloud (~3 pc) that contains multiple compact molecular cores (5+; <0.4 pc). In this study we detect a total of 15 molecular transitions in M0.10-0.08 from the following molecules: NH3, HC3N, CH3OH, HC5N, CH3CN, and OCS. We have identified more than sixty 36 GHz CH3OH masers in M0.10-0.08 with brightness temperatures above 400 K and 31 maser candidates with temperatures between 100-400 K. We conduct a kinematic analysis of the gas using NH3 and detect multiple velocity components towards this region of the Galactic center. The bulk of the gas in this region has a velocity of 51.5 km/s (M0.10-0.08) with a lower velocity wing at 37.6 km/s. We also detect a relatively faint velocity component at 10.6 km/s that we attribute to being an extension of the M0.11-0.11 cloud. Analysis of the gas kinematics, combined with past X-ray fluorescence observations, suggests M0.10-0.08 and M0.11-0.11 are located in the same vicinity of the Galactic center and could be physically interacting.Comment: Accepted for publication in the Astrophysical Journa

Molecular Gas Near Unusual Galactic Center Radio Source N3

Near the Galactic center, the presence of the supermassive black hole, high dust temperatures, and large densities produce an unique environment within our galaxy. Unfortunately, optical light in this region is obscured by dust, making optical observations difficult or impossible. By utilizing radio telescopes, we can peer through the dust to examine the inner workings of this fascinating region. Using the Very Large Array, we examined the Galactic center radio source N3, a point source located within the Radio Arc. Our observations examined both molecular line and continuum emission from the region at frequencies from 2 GHz to 49 GHz. Several molecular species are detected around N3. Using molecular line analysis, N3's spectral index, physical size limits, and possible interactions between N3 and the Radio Arc, we examine the physical nature of N3 and outline further work needed to complete the analysis of this interesting source

Frederick Rolfe’s Christmas cards: popular culture and the construction of queerness in late Victorian Britain

This article explores how the British writer and artist Frederick Rolfe (1860–1913) made use of images derived from popular visual culture to construct and express a queer identity that attempted to combine cultural, religious and sexual deviance. He made particular use of practices of bricolage of images and artefacts, as can be seen from both his photographs and novels. The Christmas cards that he posted into a scrapbook in the early 1880s can be analysed as evidencing his development of a particular form of queer aesthetic self-expression. This article argues that satires – one of these cards was a satire on clerical effeminacy – have increasingly been seen in a positive light as being implicated in the very practices of deviance that they appear to denounce. However, in relation to aestheticism such arguments may have been taken too far, because of the inherently anti-aesthetic drive of visual satire towards the grotesque. It is suggested that it was only in Rolfe’s final years, when he emerged from the quasi-ecclesiastical closet and developed an intense sex life in Venice, that he found a new confidence to depict himself in ways that were less reliant on stereotypes derived from popular culture and which relied on appropriation of the signs of manly normativity rather than on the suggestive juxtaposition of attributes of deviance