Caste and democracy: the politics of exclusion and inclusion

Der Verfasser spricht zwei Aspekte in der Debatte um das Kastensystem in Indien an. Der erste Aspekt betrifft das Kastensystem als Mechanismus sozialer Exklusion. Das Kastensystem muss als sakralisierte Machtstruktur verstanden werden, bei der die Vererbung des Kastenstatus dazu führt, dass sich diese Struktur selbst reproduziert. Kasten bilden gleichzeitig ein Netzwerk ethnischer Gemeinschaften, sie sind aber flexibel genug, um neue Bevölkerungsgruppen (Einwanderer) und neue Berufsgruppen integrieren zu können. Die dominante Position der Kongresspartei war das Ergebnis des gelungenen Versuchs, Kastenpolitik und nationalistische Ideologie zu verknüpfen. Mit ihrer Politik der "affirmative action" leistete sie einen Beitrag zur Politisierung der Kasten und zur gleichzeitigen Entritualisierung der Beziehung der Kasten untereinander. An die Stelle der rituellen Hierarchie geschlossener Statusgruppen tritt ein offenes System sozialer Schichtung, in dem beispielsweise die Zugehörigkeit zu den neuen Mittelschichten Mitgliedern aller Kasten offen steht. Die demokratische Politik hat insgesamt zu einer Säkularisierung des Kastensystems geführt. (ICE)"Caste is the most intensively and widely studied South Asian institution and there is no need to reiterate the established wisdom here. The author wishs to focus on, rather attempt to reformulate, some propositions on caste in terms that can facilitate a more direct and precise understanding of the contemporary structures of social exclusion in India. Before he proceeds with this exercise two important, even if obvious, points need to be underlined. First, while many new forms of exclusion are indeed structurally integral to the caste system, there also are those unrelated to caste as well as the ones representing a combination of caste and non-caste elements. Second, in making of a social policy for combating exclusion, it is crucial to take account of both, the changed political-cultural context of exclusion (modernity, nation-state and democracy) and the ideological and structural changes that have occurred in the caste-system itself (Sheth 2002)." (excerpt

Unbiased estimates of galaxy scaling relations from photometric redshift surveys

Many physical properties of galaxies correlate with one another, and these correlations are often used to constrain galaxy formation models. Such correlations include the color-magnitude relation, the luminosity-size relation, the Fundamental Plane, etc. However, the transformation from observable (e.g. angular size, apparent brightness) to physical quantity (physical size, luminosity), is often distance-dependent. Noise in the distance estimate will lead to biased estimates of these correlations, thus compromising the ability of photometric redshift surveys to constrain galaxy formation models. We describe two methods which can remove this bias. One is a generalization of the V_max method, and the other is a maximum likelihood approach. We illustrate their effectiveness by studying the size-luminosity relation in a mock catalog, although both methods can be applied to other scaling relations as well. We show that if one simply uses photometric redshifts one obtains a biased relation; our methods correct for this bias and recover the true relation

Isolating Geometry in Weak Lensing Measurements

Given a foreground galaxy-density field or shear field, its cross-correlation with the shear field from a background population of source galaxies scales with the source redshift in a way that is specific to lensing. Such a source-scaling can be exploited to effectively measure geometrical distances as a function of redshift and thereby constrain dark energy properties, free of any assumptions about the galaxy-mass/mass power spectrum (its shape, amplitude or growth). Such a geometrical method can yield a ~ 0.03 - 0.07 f_{sky}^{-1/2} measurement on the dark energy abundance and equation of state, for a photometric redshift accuracy of dz ~ 0.01 - 0.05 and a survey with median redshift of ~ 1. While these constraints are weaker than conventional weak lensing methods, they provide an important consistency check because the geometrical method carries less theoretical baggage: there is no need to assume any structure formation model (e.g. CDM). The geometrical method is at the most conservative end of a whole spectrum of methods which obtain smaller errorbars by making more restrictive assumptions -- we discuss some examples. Our geometrical approach differs from previous investigations along similar lines in three respects. First, the source-scaling we propose to use is less demanding on the photometric redshift accuracy. Second, the scaling works for both galaxy-shear and shear-shear correlations. Third, we find that previous studies underestimate the statistical errors associated with similar geometrical methods, the origin of which is discussed.Comment: 13 pages, 4 figures, submitted to Ap

Redshift space 21 cm power spectra from reionization

We construct a simple but self-consistent analytic ionization model for rapid exploration of 21cm power spectrum observables in redshift space. It is fully described by the average ionization fraction $x_e(z)$ and HII patch size $R(z)$ and has the flexibility to accommodate various reionization scenarios. The model associates ionization regions with dark matter halos of the number density required to recover $x_e$ and treats redshift space distortions self-consistently with the virial velocity of such halos. Based on this model, we study the line-of-sight structures in the brightness fluctuations since they are the most immune to foreground contamination. We explore the degeneracy between the HII patch size and nonlinear redshift space distortion in the one dimensional power spectrum. We also discuss the limitations experimental frequency and angular resolutions place on their distinguishability. Angular resolution dilutes even the radial signal and will be a serious limitation for resolving small bubbles before the end of reionization. Nonlinear redshift space distortions suggest that a resolution of order 1 -- 10\arcsec and a frequency resolution of 10kHz will ultimately be desirable to extract the full information in the radial field at $z\sim 10$. First generation instruments such as LOFAR and MWA can potentially measure radial HII patches of a few comoving Mpc and larger at the end of reionization and are unlikely to be affected by nonlinear redshift space distortions.Comment: 13 pages, 10 figures. Revised version. Includes minor changes. Adds appendix on accomodating a distribution of radii for the HII regions. Accepted for publication in Ap

Comparative Analysis of Molecular Clouds in M31, M33 and the Milky Way

We present BIMA observations of a 2\arcmin field in the northeastern spiral arm of M31. In this region we find six giant molecular clouds that have a mean diameter of 57$\pm$13 pc, a mean velocity width of 6.5$\pm$1.2 \kms, and a mean molecular mass of 3.0 $\pm$ 1.6 $\times$ 10$^5$\Msun. The peak brightness temperature of these clouds ranges from 1.6--4.2 K. We compare these clouds to clouds in M33 observed by \citet{wilson90} using the OVRO millimeter array, and some cloud complexes in the Milky Way observed by \cite{dame01} using the CfA 1.2m telescope. In order to properly compare the single dish data to the spatially filtered interferometric data, we project several well-known Milky Way complexes to the distance of Andromeda and simulate their observation with the BIMA interferometer. We compare the simulated Milky Way clouds with the M31 and M33 data using the same cloud identification and analysis technique and find no significant differences in the cloud properties in all three galaxies. Thus we conclude that previous claims of differences in the molecular cloud properties between these galaxies may have been due to differences in the choice of cloud identification techniques. With the upcoming CARMA array, individual molecular clouds may be studied in a variety of nearby galaxies. With ALMA, comprehensive GMC studies will be feasible at least as far as the Virgo cluster. With these data, comparative studies of molecular clouds across galactic disks of all types and between different galaxy disks will be possible. Our results emphasize that interferometric observations combined with the use of a consistent cloud identification and analysis technique will be essential for such forthcoming studies that will compare GMCs in the Local Group galaxies to galaxies in the Virgo cluster.Comment: Accepted for Publication in the Astrophysical Journa

A Spitzer Unbiased Ultradeep Spectroscopic Survey

We carried out an unbiased, spectroscopic survey using the low-resolution module of the infrared spectrograph (IRS) on board Spitzer targeting two 2.6 square arcminute regions in the GOODS-North field. IRS was used in spectral mapping mode with 5 hours of effective integration time per pixel. One region was covered between 14 and 21 microns and the other between 20 and 35 microns. We extracted spectra for 45 sources. About 84% of the sources have reported detections by GOODS at 24 microns, with a median F_nu(24um) ~ 100 uJy. All but one source are detected in all four IRAC bands, 3.6 to 8 microns. We use a new cross-correlation technique to measure redshifts and estimate IRS spectral types; this was successful for ~60% of the spectra. Fourteen sources show significant PAH emission, four mostly SiO absorption, eight present mixed spectral signatures (low PAH and/or SiO) and two show a single line in emission. For the remaining 17, no spectral features were detected. Redshifts range from z ~ 0.2 to z ~ 2.2, with a median of 1. IR Luminosities are roughly estimated from 24 microns flux densities, and have median values of 2.2 x 10^{11} L_{\odot} and 7.5 x 10^{11} L_{\odot} at z ~ 1 and z ~ 2 respectively. This sample has fewer AGN than previous faint samples observed with IRS, which we attribute to the fainter luminosities reached here.Comment: Published in Ap

A people-oriented paradigm for smart cities

Most works in the literature agree on considering the Internet of Things (IoT) as the base technology to collect information related to smart cities. This information is usually offered as open data for its analysis, and to elaborate statistics or provide services which improve the management of the city, making it more efficient and more comfortable to live in. However, it is not possible to actually improve the quality of life of smart cities’ inhabitants if there is no direct information about them and their experiences. To address this problem, we propose using a social and mobile computation model, called the Internet of People (IoP) which empowers smartphones to recollect information about their users, analyze it to obtain knowledge about their habits, and provide this knowledge as a service creating a collaborative information network. Combining IoT and IoP, we allow the smart city to dynamically adapt its services to the needs of its citizens, promoting their welfare as the main objective of the city.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Spatially Resolved Spitzer-IRS Spectral Maps of the Superwind in M82

We have mapped the superwind/halo region of the nearby starburst galaxy M82 in the mid-infrared with $Spitzer-IRS$. The spectral regions covered include the H$_2 S(1)-S(3)$, [NeII], [NeIII] emission lines and PAH features. We estimate the total warm H$_2$ mass and the kinetic energy of the outflowing warm molecular gas to be between $M_{warm}\sim5-17\times10^6$ M$_{\odot}$ and $E_{K}\sim6-20\times10^{53}$ erg. Using the ratios of the 6.2, 7.7 and 11.3 micron PAH features in the IRS spectra, we are able to estimate the average size and ionization state of the small grains in the superwind. There are large variations in the PAH flux ratios throughout the outflow. The 11.3/7.7 and the 6.2/7.7 PAH ratios both vary by more than a factor of five across the wind region. The Northern part of the wind has a significant population of PAH's with smaller 6.2/7.7 ratios than either the starburst disk or the Southern wind, indicating that on average, PAH emitters are larger and more ionized. The warm molecular gas to PAH flux ratios (H$_2/PAH$) are enhanced in the outflow by factors of 10-100 as compared to the starburst disk. This enhancement in the H$_2/PAH$ ratio does not seem to follow the ionization of the atomic gas (as measured with the [NeIII]/[NeII] line flux ratio) in the outflow. This suggests that much of the warm H$_2$ in the outflow is excited by shocks. The observed H$_2$ line intensities can be reproduced with low velocity shocks ($v < 40$ km s$^{-1}$) driven into moderately dense molecular gas ($10^2 <n_H < 10^4$ cm$^{-3}$) entrained in the outflow.Comment: 19 pages and 12 figures; accepted in MNRA

The Size and Shape of Voids in Three-Dimensional Galaxy Surveys

The sizes and shapes of voids in a galaxy survey depend not only on the physics of structure formation, but also on the sampling density of the survey and on the algorithm used to define voids. Using an N-body simulation with a CDM power spectrum, we study the properties of voids in samples with different number densities of galaxies, both in redshift space and in real space. When voids are defined as regions totally empty of galaxies, their characteristic volume is strongly dependent on sampling density; when they are defined as regions whose density is 0.2 times the mean galaxy density, the dependence is less strong. We compare two void-finding algorithms, one in which voids are nonoverlapping spheres, and one, based on the algorithm of Aikio and Mahonen, which does not predefine the shape of a void. Regardless of the algorithm chosen, the characteristic void size is larger in redshift space than in real space, and is larger for low sampling densities than for high sampling densities. We define an elongation statistic Q which measures the tendency of voids to be stretched or squashed along the line of sight. Using this statistic, we find that at sufficiently high sampling densities (comparable to the number densities of galaxies brighter than L_*), large voids tend to be slightly elongated along the line of sight in redshift space.Comment: LaTex, 21 pages (including 7 figures), ApJ, submitte