The Evolution, Cost, and Operation of the Private Food Assistance Network

Delivery of assistance to the poor has changed drastically in the past 20 years. While the availability of cash assistance has decreased, the availability of food assistance has widened. The most substantial change in assistance available to the poor may have been the emergence of food pantries as a source of free food to prepare at home. Large numbers of Americans rely on food pantries, but many policymakers, academics, and participants in the private food assistance network have limited understanding of the network. This paper aims to fill that gap by examining how the network evolved, how much it costs, and how it operates. We provide a detailed review of domestic food policy since the 1930s, show how agricultural and welfare policies contributed to developing a supply of free food available to the needy, and explain how private efforts, such as the creation of Second Harvest, resulted in a rise in food pantries. Our research also highlights policy changes in the Food Stamp program that may have contributed to the tremendous demand for free food in the 1980s. Using secondary data, we estimate that the private food assistance network costs about $2.3 billion annually, making it about one-twelfth the size of the Food Stamp program. We show that the benefits available to the needy from the network differ among geographic areas. We highlight the heterogeneity of organizations in the network by examining two food banks, the Connecticut Food Bank and the Greater Pittsburgh Community Food Bank. We conclude that the private food assistance network provides the needy with valuable resources and offer recommendations for making the public food safety net more effective.

Follow-Up Chandra Observations of Three Candidate Tidal Disruption Events

Large-amplitude, high-luminosity soft X-ray flares were detected by the ROSAT All-Sky Survey in several galaxies with no evidence of Seyfert activity in their ground-based optical spectra. These flares had the properties predicted for a tidal disruption of a star by a central supermassive black hole. We report Chandra observations of three of these galaxies taken a decade after their flares that reveal weak nuclear X-ray sources that are from 240 to 6000 times fainter than their luminosities at peak, supporting the theory that these were special events and not ongoing active galactic nucleus (AGN) variability. The decline of RX J1624.9+7554 by a factor of 6000 is consistent with the (t-t_D)^(-5/3) decay predicted for the fall-back phase of a tidal disruption event, but only if ROSAT was lucky enough to catch the event exactly at its peak in 1990 October. RX J1242.6-1119A has declined by a factor of 240, also consistent with (t-t_D)^(-5/3). In the H II galaxy NGC 5905 we find only resolved, soft X-ray emission that is undoubtedly associated with starburst activity. When accounting for the starburst component, the ROSAT observations of NGC 5905, as well as the Chandra upper limit on its nuclear flux, are consistent with a (t-t_D)^(-5/3) decay by at least a factor of 1000. Although we found weak Seyfert~2 emission lines in Hubble Space Telescope spectra of NGC 5905, indicating that a low-luminosity AGN was present prior to the X-ray flare, we favor a tidal disruption explanation for the flare itself.Comment: 17 pages, 4 figures, to appear in ApJ April 1 200

X-ray Spectroscopy of QSOs with Broad Ultraviolet Absorption Lines

For the population of QSOs with broad ultraviolet absorption lines, we are just beginning to accumulate X-ray observations with enough counts for spectral analysis at CCD resolution. From a sample of eight QSOs [including four Broad Absorption Line (BAL) QSOs and three mini-BAL QSOs] with ASCA or Chandra spectra with more than 200 counts, general patterns are emerging. Their power-law X-ray continua are typical of normal QSOs with Gamma~2.0, and the signatures of a significant column density [N_H~(0.1-4)x10^{23} cm^{-2}] of intrinsic, absorbing gas are clear. Correcting the X-ray spectra for intrinsic absorption recovers a normal ultraviolet-to-X-ray flux ratio, indicating that the spectral energy distributions of this population are not inherently anomalous. In addition, a large fraction of our sample shows significant evidence for complexity in the absorption. The subset of BAL QSOs with broad MgII absorption apparently suffers from Compton-thick absorption completely obscuring the direct continuum in the 2-10 keV X-ray band, complicating any measurement of their intrinsic X-ray spectral shapes.Comment: 9 pages, 6 figures, uses AASTeX. Accepted to the Astrophysical Journa

The Giant X-Ray Flare of NGC 5905: Tidal Disruption of a Star, a Brown Dwarf, or a Planet?

We model the 1990 giant X-ray flare of the quiescent galaxy NGC 5905 as the tidal disruption of a star by a supermassive black hole. From the observed rapid decline of the luminosity, over a timescale of a few years, we argue that the flare was powered by the fallback of debris rather than subsequent accretion via a thin disk. The fallback model allows constraints to be set on the black hole mass and the mass of debris. The latter must be very much less than a solar mass to explain the very low luminosity of the flare. The observations can be explained either as the partial stripping of the outer layers of a low-mass main sequence star or as the disruption of a brown dwarf or a giant planet. We find that the X-ray emission in the flare must have originated within a small patch rather than over the entire torus of circularized material surrounding the black hole. We suggest that the patch corresponds to the ``bright spot'' where the stream of returning debris impacts the torus. Interestingly, although the peak luminosity of the flare was highly sub-Eddington, the peak flux from the bright spot was close to the Eddington limit. We speculate on the implications of this result for observations of other flare events.Comment: 25 pages, including 5 figure

Chandra X-ray Observations of the Quadruply Lensed Quasar RX J0911.4+0551

We present results from X-ray observations of the quadruply lensed quasar RX J0911.4+0551 using data obtained with the Advanced CCD Imaging Spectrometer (ACIS) on board the Chandra X-ray Observatory. The 29 ks observation detects a total of ~404 X-ray photons (0.3 to 7.0 keV) from the four images of the lensed quasar. Deconvolution of the aspect corrected data resolves all four lensed images, with relative positions in good agreement with optical measurements. When compared to contemporaneous optical data, one of the lensed images (component A3) is dimmer by a factor of ~6 in X-rays with respect to the 2 brighter images (components A1 and A2). Spectral fitting for the combined images shows significant intrinsic absorption in the soft (0.2 to 2.4 keV) energy band, consistent with the mini-BAL nature of this quasar, while a comparison with ROSAT PSPC observations from 1990 shows a drop of ~6.5 in the total soft bandpass flux. The observations also detect ~157 X-ray photons arising from extended emission of the nearby cluster (peaked ~42" SW of RXJ0911.4+0551) responsible for the large external shear present in the system. The Chandra observation reveals the cluster emission to be complex and non-spherical, and yields a cluster temperature of kT = 2.3^{+1.8}_{-0.8} keV and a 2.0 to 10 keV cluster luminosity within a 1 Mpc radius of L_X = 7.6_{-0.2}^{+0.6} x 10^{43} ergs/s (error bars denote 90% confidence limits). Our mass estimate of the cluster within its virial radius is 2.3^{+1.8}_{-0.7} x 10^{14} solar, and is a factor of 2 smaller than, although consistent with, previous mass estimates based on the observed cluster velocity dispersion.Comment: 16 pages, 3 figures (figure 1 is color ps). Accepted by Ap

Unified Field Theory From Enlarged Transformation Group. The Covariant Derivative for Conservative Coordinate Transformations and Local Frame Transformations

Pandres has developed a theory in which the geometrical structure of a real four-dimensional space-time is expressed by a real orthonormal tetrad, and the group of diffeomorphisms is replaced by a larger group called the conservation group. This paper extends the geometrical foundation for Pandres' theory by developing an appropriate covariant derivative which is covariant under all local Lorentz (frame) transformations, including complex Lorentz transformations, as well as conservative transformations. After defining this extended covariant derivative, an appropriate Lagrangian and its resulting field equations are derived. As in Pandres' theory, these field equations result in a stress-energy tensor that has terms which may automatically represent the electroweak field. Finally, the theory is extended to include 2-spinors and 4-spinors.Comment: Aug 25 replacement has corrected margin width

Divergent platforms

Models of electoral competition between two opportunistic, office-motivated parties typically predict that both parties become indistinguishable in equilibrium. I show that this strong connection between the office motivation of parties and their equilibrium choice of identical platforms depends on two—possibly false—assumptions: (1) Issue spaces are uni-dimensional and (2) Parties are unitary actors whose preferences can be represented by expected utilities. I provide an example of a two-party model in which parties offer substantially different equilibrium platforms even though no exogenous differences between parties are assumed. In this example, some voters’ preferences over the 2-dimensional issue space exhibit non-convexities and parties evaluate their actions with respect to a set of beliefs on the electorate

Two New Gravitationally Lensed Double Quasars from the Sloan Digital Sky Survey

We report the discoveries of the two-image gravitationally lensed quasars, SDSS J0746+4403 and SDSS J1406+6126, selected from the Sloan Digital Sky Survey (SDSS). SDSS J0746+4403, which will be included in our lens sample for statistics and cosmology, has a source redshift of z_s=2.00, an estimated lens redshift of z_l~0.3, and an image separation of 1.08". SDSS J1406+6126 has a source redshift of z_s=2.13, a spectroscopically measured lens redshift of z_l=0.27, and an image separation of 1.98". We find that the two quasar images of SDSS J1406+6126 have different intervening MgII absorption strengths, which are suggestive of large variations of absorbers on kpc scales. The positions and fluxes of both the lensed quasar systems are easily reproduced by simple mass models with reasonable parameter values. These objects bring to 18 the number of lensed quasars that have been discovered from the SDSS data.Comment: 25 pages, 6 figures, The Astronomical Journal accepte

RX J0911+05: A Massive Cluster Lens at z=0.769

We report the detection of a massive high-redshift cluster of galaxies near the quadruple quasar RX J0911+05, using the LRIS instrument on the Keck-II telescope. The cluster is found to have a mean redshift of =0.7689+/-0.002 and a velocity dispersion of sigma=836{+180-200} km/s, based on redshift measurements for 24 member galaxies. This massive high-redshift cluster is the origin of the unusually large external shear required by lensing models of the quadruple quasar system. We predict the expected time delay depending on the exact contribution of the cluster. A measurement of the time delay and further deep lensing and X-ray observations will unravel useful properties of this serendipitously discovered high-redshift cluster, and may put interesting cosmological constraints on H0.Comment: Submitted to ApJL, 7 pages, 5 figure

UV/Optical Detections of Candidate Tidal Disruption Events by GALEX and CFHTLS

We present two luminous UV/optical flares from the nuclei of apparently inactive early-type galaxies at z=0.37 and 0.33 that have the radiative properties of a flare from the tidal disruption of a star. In this paper we report the second candidate tidal disruption event discovery in the UV by the GALEX Deep Imaging Survey, and present simultaneous optical light curves from the CFHTLS Deep Imaging Survey for both UV flares. The first few months of the UV/optical light curves are well fitted with the canonical t^(-5/3) power-law decay predicted for emission from the fallback of debris from a tidally disrupted star. Chandra ACIS X-ray observations during the flares detect soft X-ray sources with T_bb= (2-5) x 10^5 K or Gamma > 3 and place limits on hard X-ray emission from an underlying AGN down to L_X (2-10 keV) <~ 10^41 ergs/s. Blackbody fits to the UV/optical spectral energy distributions of the flares indicate peak flare luminosities of > 10^44-10^45 ergs/s. The temperature, luminosity, and light curves of both flares are in excellent agreement with emission from a tidally disrupted main sequence star onto a central black hole of several times 10^7 msun. The observed detection rate of our search over ~ 2.9 deg^2 of GALEX Deep Imaging Survey data spanning from 2003 to 2007 is consistent with tidal disruption rates calculated from dynamical models, and we use these models to make predictions for the detection rates of the next generation of optical synoptic surveys.Comment: 28 pages, 27 figures, 11 tables, accepted to ApJ, final corrections from proofs adde