Spartan Daily, January 17, 1935

Volume 23, Issue 64https://scholarworks.sjsu.edu/spartandaily/2243/thumbnail.jp

On the origin of M81 group extended dust emission

Galactic cirrus emission at far-infrared wavelengths affects many extragalactic observations. Separating this emission from that associated with extragalactic objects is both important and difficult. In this paper we discuss a particular case, the M81 group, and the identification of diffuse structures prominent in the infrared, but also detected at optical wavelengths. The origin of these structures has previously been controversial, ranging from them being the result of a past interaction between M81 and M82 or due to more local Galactic emission. We show that over an order of a few arcmin scales, the far-infrared (Herschel 250 mu m) emission correlates spatially very well with a particular narrow-velocity (2-3 km s(-1)) component of the Galactic HI. We find no evidence that any of the far-infrared emission associated with these features actually originates in the M81 group. Thus we infer that the associated diffuse optical emission must be due to galactic light-back scattered off dust in our galaxy. Ultraviolet observations pick out young stellar associations around M81, but no detectable far-infrared emission. We consider in detail one of the Galactic cirrus features, finding that the far-infrared HI relation breaks down below arcmin scales and that at smaller scales there can be quite large dust-temperature variation

Probing the Galaxy's bars via the Hercules stream

It has been suggested that a resonance between a rotating bar and stars in the solar neighbourhood can produce the so called 'Hercules stream'. Recently, a second bar may have been identified in the Galactic centre, the so called 'long bar', which is longer and much flatter than the traditional Galactic bar, and has a similar mass. We looked at the dynamical effects of both bars, separately and together, on orbits of stars integrated backwards from local position and velocities, and a model of the Galactic potential which includes the bars directly. Both bars can produce Hercules like features, and allow us to measure the rotation rate of the bar(s). We measure a pattern speed, for both bars, of 1.87 +/- 0.02 times the local circular frequency. This is on par with previous measurements for the Galactic bar, although we do adopt a slightly different Solar motion. Finally, we identify a new kinematic feature in local velocity space, caused by the long bar, which is tempting to identify with the high velocity 'Arcturus' stream.Comment: 9 pages, 10 figures, Accepted to MNRAS, Corrected for errat

A slow bar in the dwarf irregular galaxy NGC 3741

Using the Tremaine-Weinberg method, we measure the speed of the HI bar seen in the disk of NGC 3741. NGC 3741 is an extremely gas rich galaxy with an {H\,{\sc i}} disk which extends to about 8.3 times its Holmberg radius. It is also highly dark matter-dominated. Our calculated value of the pattern speed $\Omega_p$ is 17.1 $\pm$ 3.4 km $\textrm{s}^{-1}\textrm{kpc}^{-1}$. We also find the ratio of the co-rotation radius to the bar semi-major axis to be (1.6 $\pm$ 0.3), indicating a slow bar. This is consistent with bar models in which dynamical friction results in a slow bar in dark matter dominated galaxies.Comment: 7 pages, 4 figures, 2 tables Accepted for publlication in MNRA

An Ultraviolet-to-Radio Broadband Spectral Atlas of Nearby Galaxies

The ultraviolet-to-radio continuum spectral energy distributions are presented for all 75 galaxies in the Spitzer Infrared Nearby Galaxies Survey (SINGS). A principal component analysis of the sample shows that most of the sample's spectral variations stem from two underlying components, one representative of a galaxy with a low infrared-to-ultraviolet ratio and one representative of a galaxy with a high infrared-to-ultraviolet ratio. The influence of several parameters on the infrared-to-ultraviolet ratio is studied (e.g., optical morphology, disk inclination, far-infrared color, ultraviolet spectral slope, and star formation history). Consistent with our understanding of normal star-forming galaxies, the SINGS sample of galaxies in comparison to more actively star-forming galaxies exhibits a larger dispersion in the infrared-to-ultraviolet versus ultraviolet spectral slope correlation. Early type galaxies, exhibiting low star formation rates and high optical surface brightnesses, have the most discrepant infrared-to-ultraviolet correlation. These results suggest that the star formation history may be the dominant regulator of the broadband spectral variations between galaxies. Finally, a new discovery shows that the 24 micron morphology can be a useful tool for parametrizing the global dust temperature and ultraviolet extinction in nearby galaxies. The dust emission in dwarf/irregular galaxies is clumpy and warm accompanied by low ultraviolet extinction, while in spiral galaxies there is typically a much larger diffuse component of cooler dust and average ultraviolet extinction. For galaxies with nuclear 24 micron emission, the dust temperature and ultraviolet extinction are relatively high compared to disk galaxies.Comment: Accepted for publication in the Astrophysical Journal; Fixed radio flux density units (mJy

Homeric Studies, Feminism, and Queer Theory: Interpreting Helen and Penelope

Nancy Sorkin Rabinowitz and Amy Richlin’s Feminist Theory and the Classics (1993) and Barbara F. McManus’ Classics and Feminism: Gendering the Classics (1997) provided ground-breaking surveys of the feminist revolution in classical studies, and their work leads us to the question of the feminist impact on the study of Homer. In this essay, I review the contributions of feminist scholarship on Homer and explore queer theory as a new heuristic avenue for advancing the feminist interpretation of the Homeric epics. With this approach, I follow upon and revise McManus’ use of the concept of “dual-gendering” (a term that I employ instead of her original “transgendered,” as I explain below) for her feminist analysis of Virgil’s Latin epic, the Aeneid. Her interpretive lens encourages us to look for complexity in epic gender representation and to investigate the ideological functions of this representation; my deployment of queer theory reframes her line of inquiry in terms of the gender normative and deviant and includes in its purview the additional categories of sexuality and power relations. [excerpt

Spartan Daily, January 30, 1936

Volume 24, Issue 71https://scholarworks.sjsu.edu/spartandaily/2399/thumbnail.jp

The fragility of planetary systems

We specify the range to which perturbations penetrate a planetesimal system. Such perturbations can originate from massive planets or from encounters with other stars. The latter can have an origin in the star cluster in which the planetary system was born, or from random encounters once the planetary system has escaped its parental cluster. The probability of a random encounter, either in a star cluster or in the Galactic field depends on the local stellar density, the velocity dispersion and the time spend in that environment. By adopting order of magnitude estimates we argue that the majority of planetary systems born in open clusters will have a {\em Parking zone}, in which planetesimals are affected by encounters in their parental star cluster but remain unperturbed after the star has left the cluster. Objects found in this range of semi-major axis and eccentricity preserve the memory of the encounter that last affected their orbits, and they can therefore be used to reconstruct this encounter. Planetary systems born in a denser environment, such as in a globular cluster are unlikely to have a Parking zone. We further argue that some planetary systems may have a {\em Frozen zone}, in which orbits are not affected either by the more inner massive planets or by external influences. Objects discovered in this zone will have preserved information about their formation in their orbital parameters.Comment: 4 pages, accepted for publication in MNRA

Free relative constructions in OT syntax

This paper is part of a research project on OT Syntax and the typology of the free relative (FR) construction. It concentrates on the details of an OT analysis and some of its consequences for OT syntax. I will not present a general discussion of the phenomenon and the many controversial issues it is famous for in generative syntax