J. Gallagher

IceCube search for dark matter annihilation in nearby galaxies and galaxy clusters

We present the results of a first search for self-annihilating dark matter in nearby galaxies and galaxy clusters using a sample of high-energy neutrinos acquired in 339.8 days of live time during 2009/10 with the IceCube neutrino observatory in its 59-string configuration. The targets of interest include the Virgo and Coma galaxy clusters, the Andromeda galaxy, and several dwarf galaxies. We obtain upper limits on the cross section as a function of the weakly interacting massive particle mass between 300 GeV and 100 TeV for the annihilation into b (b) over bar, W+(W) over bar (-), tau(+)tau(-), mu(+)mu(-) , and nu(nu) over bar. A limit derived for the Virgo cluster, when assuming a large effect from subhalos, challenges the weakly interacting massive particle interpretation of a recently observed GeV positron excess in cosmic rays.

Observation of the cosmic-ray shadow of the Moon with IceCube

We report on the observation of a significant deficit of cosmic rays from the direction of the Moon with the IceCube detector. The study of this Moon shadow is used to characterize the angular resolution and absolute pointing capabilities of the detector. The detection is based on data taken in two periods before the completion of the detector: between April 2008 and May 2009, when IceCube operated in a partial configuration with 40 detector strings deployed in the South Pole ice, and between May 2009 and May 2010 when the detector operated with 59 strings. Using two independent analysis methods, the Moon shadow has been observed to high significance (> 6 sigma) in both detector configurations. The observed location of the shadow center is within 0.2 degrees of its expected position when geomagnetic deflection effects are taken into account. This measurement validates the directional reconstruction capabilities of IceCube.

Lowering IceCube’s energy threshold for point source searches in the southern sky

Observation of a point source of astrophysical neutrinos would be a smoking gun signature of a cosmic-ray accelerator. While IceCube has recently discovered a diffuse flux of astrophysical neutrinos, no localized point source has been observed. Previous IceCube searches for point sources in the southern sky were restricted by either an energy threshold above a few hundred TeV or poor neutrino angular resolution. Here we present a search for southern sky point sources with greatly improved sensitivities to neutrinos with energies below 100 TeV. By selecting charged-current ν μ interacting inside the detector, we reduce the atmospheric background while retaining efficiency for astrophysical neutrino-induced events reconstructed with sub-degree angular resolution. The new event sample covers three years of detector data and leads to a factor of 10 improvement in sensitivity to point sources emitting below 100 TeV in the southern sky. No statistically significant evidence of point sources was found, and upper limits are set on neutrino emission from individual sources. A posteriori analysis of the highest-energy (∼100 TeV) starting event in the sample found that this event alone represents a 2.8σ deviation from the hypothesis that the data consists only of atmospheric background.

Search for ultrahigh-energy tau neutrinos with IceCube

The first dedicated search for ultrahigh-energy (UHE) tau neutrinos of astrophysical origin was performed using the IceCube detector in its 22-string configuration with an instrumented volume of roughly 0: 25 km(3). The search also had sensitivity to UHE electron and muon neutrinos. After application of all selection criteria to approximately 200 live-days of data, we expect a background of 0.60 +/- 0.19(stat)(-0.58)(+0.56)(syst) events and observe three events, which after inspection, emerge as being compatible with background but are kept in the final sample. Therefore, we set an upper limit on neutrinos of all flavors from UHE astrophysical sources at 90% C.L. of E-v(2)Phi(90)(v(x)) < 16.3 x 10(-8) GeV cm(-2) sr(-1) s(-1) over an estimated primary neutrino energy range of 340 TeV to 200 PeV.

The Great War and the female gaze: Edith Wharton and the iconography of war propaganda

(1996). The great war and the female gaze: Edith Wharton and the iconography of war propaganda. Lit: Literature Interpretation Theory: Vol. 7, No. 1, pp. 27-49.

The World Wars through the Female Gaze

For some women writers and photographers during the two world wars - Edith Wharton, Mildred Aldrich, Martha Gellhorn, Lee Miller, H.D. and Gertrude Stein - the construction of the female subject as an observer of combat became a vital concern. Their explorations of vision took place against the backdrop of a larger shift in Western cultures understanding of what seeing meant in common practice and philosophical discourse alike. The role of visuality in their lives was transformed not only by the rigid gender roles of war but by the introduction of new combat practices and technologies such as aerial surveillance, trench warfare and civilian bombardment. In The World Wars Through the Female Gaze, Jean Gallagher maps one portion of the historicized, gendered territory of what Nancy K. Miller calls the gaze in representation. Expanding the notion of the gaze in critical discourse, Gallagher situates a number of visual acts within specific historic contexts to reconstruct the wartime female subject. She looks at both the female observers physical act of seeing - and the refusal to see - for example, a battlefield, a wounded soldier, a torture victim, a national flag, a fashion model, a bombed city, or a wartime hallucination. The book begins with two instances of wartime propaganda written by American women in France in 1915. Both Edith Whartons Fighting France and Mildred Aldrichs A Hilltop on the Marne offer a complex and often contradictory sense of a woman writers struggles with authority, resistance and killing. In the process, Gallagher teases out the role of specular vision and the impossibility of directly seeing the war. Gallagher then turns to literary and visual texts produced by two female journalists between 1940 and 1945. Martha Gellhorns 1940 novel A Stricken Field exhibits a range of gendered seeing positions within and in opposition to the visual ideologies of fascism during the Nazi occupation of Cezchoslovakia. Lee Millers war correspondence and photography for Vogue show how Miller constructed herself and her predominantly female American audience as antifascist observers of war by working with and against some of the conventions of surrealist fashion photography. Gallagher concludes by focusing on the experimental autobiographical prose of H.D. and Gertrude Stein to explore the functions of vision on two World War II homefronts - London during the Blitz and Vichy France.