164 research outputs found
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Human Rights Conventions
Human rights conventions codify a wide range of rights and standards under international law. However, plagued by polarizing disagreements about human rights, views about human rights conventions are equally divided. The main strands of skepticism of human rights conventions are mainly about the pitfalls of the legalization of human rights and ineffectiveness of international instruments and institutions in implementing human rights standards and improving compliance, despite their criticized proliferation. But apart from the skeptical views about what can be more generally described as the praxis of human rights conventions, they also give rise to more fundamental and major philosophical issues. These, for example, include the ability of human rights conventions to clarify the content of human rights or the point and normative justification of having conventions. After providing an overview of conventions, this entry will engage primarily with the former issue and argue..
Kpc-scale Properties of Emission-line Galaxies
We perform a detailed study of the resolved properties of emission-line
galaxies at kpc-scale to investigate how small-scale and global properties of
galaxies are related. 119 galaxies with high-resolution Keck/DEIMOS spectra are
selected to cover a wide range in morphologies over the redshift range
0.2<z<1.3. Using the HST/ACS and HST/WFC3 imaging data taken as a part of the
CANDELS project, for each galaxy we perform SED fitting per resolution element,
producing resolved rest-frame U-V color, stellar mass, star formation rate, age
and extinction maps. We develop a technique to identify blue and red "regions"
within individual galaxies, using their rest-frame color maps. As expected, for
any given galaxy, the red regions are found to have higher stellar mass surface
densities and older ages compared to the blue regions. Furthermore, we quantify
the spatial distribution of red and blue regions with respect to both redshift
and stellar mass, finding that the stronger concentration of red regions toward
the centers of galaxies is not a significant function of either redshift or
stellar mass. We find that the "main sequence" of star forming galaxies exists
among both red and blue regions inside galaxies, with the median of blue
regions forming a tighter relation with a slope of 1.1+/-0.1 and a scatter of
~0.2 dex compared to red regions with a slope of 1.3+/-0.1 and a scatter of
~0.6 dex. The blue regions show higher specific Star Formation Rates (sSFR)
than their red counterparts with the sSFR decreasing since z~1, driver
primarily by the stellar mass surface densities rather than the SFRs at a giver
resolution element.Comment: 17 pages, 17 figures, Submitted to the Ap
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Electoral Process in Iran: Analysis of Political Participation and Iran’s Compliance with International Human Rights Obligations
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Rule of Law in Iran: Independence of the Judiciary, Bar Association, Lawyers and Iran’s Compliance with International Human Rights Obligations
Modelling high resolution ALMA observations of strongly lensed highly star forming galaxies detected by <i>Herschel</i>
We have modelled ∼ 0.1 arcsec resolution ALMA imaging of six strong gravitationally lensed galaxies detected by the Herschel Space Observatory. Our modelling recovers mass properties of the lensing galaxies and, by determining magnification factors, intrinsic properties of the lensed sub-millimetre sources. We find that the lensed galaxies all have high ratios of star formation rate to dust mass, consistent with or higher than the mean ratio for high redshift sub-millimetre galaxies and low redshift ultra-luminous infra-red galaxies. Source reconstruction reveals that most galaxies exhibit disturbed morphologies. Both the cleaned image plane data and the directly observed interferometric visibilities have been modelled, enabling comparison of both approaches. In the majority of cases, the recovered lens models are consistent between methods, all six having mass density profiles that are close to isothermal. However, one system with poor signal to noise shows mildly significant differences
Spitzer Observations of the North Ecliptic Pole
We present a photometric catalog for Spitzer Space Telescope warm mission
observations of the North Ecliptic Pole (NEP; centered at , ). The observations are
conducted with IRAC in 3.6 m and 4.5 m bands over an area of 7.04
deg reaching 1 depths of 1.29 Jy and 0.79 Jy in the 3.6
m and 4.5 m bands respectively. The photometric catalog contains
380,858 sources with 3.6 m and 4.5 m band photometry over the
full-depth NEP mosaic. Point source completeness simulations show that the
catalog is 80% complete down to 19.7 AB. The accompanying catalog can be
utilized in constraining the physical properties of extra-galactic objects,
studying the AGN population, measuring the infrared colors of stellar objects,
and studying the extra-galactic infrared background light.Comment: 10 pages, 11 figures and 3 tables. Accepted to the ApJ
The DEIMOS 10k spectroscopic survey catalog of the COSMOS field
We present a catalog of 10718 objects in the COSMOS field observed through
multi-slit spectroscopy with the Deep Imaging Multi-Object Spectrograph
(DEIMOS) on the Keck II telescope in the wavelength range ~5500-9800A. The
catalog contains 6617 objects with high-quality spectra (two or more spectral
features), and 1798 objects with a single spectroscopic feature confirmed by
the photometric redshift. For 2024 typically faint objects we could not obtain
reliable redshifts. The objects have been selected from a variety of input
catalogs based on multi-wavelength observations in the field, and thus have a
diverse selection function, which enables the study of the diversity in the
galaxy population. The magnitude distribution of our objects is peaked at
I_AB~23 and K_AB~21, with a secondary peak at K_AB~24. We sample a broad
redshift distribution in the range 0<z<6, with one peak at z~1, and another one
around z~4. We have identified 13 redshift spikes at z>0.65 with chance
probabilities <4xE-4$, some of which are clearly related to protocluster
structures of sizes >10 Mpc. An object-to-object comparison with a multitude of
other spectroscopic samples in the same field shows that our DEIMOS sample is
among the best in terms of fraction of spectroscopic failures and relative
redshift accuracy. We have determined the fraction of spectroscopic blends to
about 0.8% in our sample. This is likely a lower limit and at any rate well
below the most pessimistic expectations. Interestingly, we find evidence for
strong lensing of Ly-alpha background emitters within the slits of 12 of our
target galaxies, increasing their apparent density by about a factor of 4.Comment: 28 pages, 11 figures and 5 tables. The full catalogue table is
available on http://cosmos.astro.caltech.edu. Accepted for publication in the
Astrophysical Journa
Beyond Spheroids and Discs: Classifications of CANDELS Galaxy Structure at 1.4 < z < 2 via Principal Component Analysis
Important but rare and subtle processes driving galaxy morphology and
star-formation may be missed by traditional spiral, elliptical, irregular or
S\'ersic bulge/disk classifications. To overcome this limitation, we use a
principal component analysis of non-parametric morphological indicators
(concentration, asymmetry, Gini coefficient, , multi-mode, intensity
and deviation) measured at rest-frame -band (corresponding to HST/WFC3 F125W
at 1.4 ) galaxy morphologies. Principal component analysis (PCA) quantifies
the correlations between these morphological indicators and determines the
relative importance of each. The first three principal components (PCs) capture
75 per cent of the variance inherent to our sample. We interpret the
first principal component (PC) as bulge strength, the second PC as dominated by
concentration and the third PC as dominated by asymmetry. Both PC1 and PC2
correlate with the visual appearance of a central bulge and predict galaxy
quiescence. PC1 is a better predictor of quenching than stellar mass, as as
good as other structural indicators (S\'ersic-n or compactness). We divide the
PCA results into groups using an agglomerative hierarchical clustering method.
Unlike S\'ersic, this classification scheme separates compact galaxies from
larger, smooth proto-elliptical systems, and star-forming disk-dominated clumpy
galaxies from star-forming bulge-dominated asymmetric galaxies. Distinguishing
between these galaxy structural types in a quantitative manner is an important
step towards understanding the connections between morphology, galaxy assembly
and star-formation.Comment: 31 pages, 24 figures, accepted for publication in MNRA
CANDELS Sheds Light on the Environmental Quenching of Low-mass Galaxies
We investigate the environmental quenching of galaxies, especially those with
stellar masses (M*), beyond the local universe. Essentially
all local low-mass quenched galaxies (QGs) are believed to live close to
massive central galaxies, which is a demonstration of environmental quenching.
We use CANDELS data to test {\it whether or not} such a dwarf QG--massive
central galaxy connection exists beyond the local universe. To this purpose, we
only need a statistically representative, rather than a complete, sample of
low-mass galaxies, which enables our study to . For each low-mass
galaxy, we measure the projected distance () to its nearest massive
neighbor (M*) within a redshift range. At a given redshift
and M*, the environmental quenching effect is considered to be observed if the
distribution of QGs () is significantly skewed toward
lower values than that of star-forming galaxies (). For galaxies
with , such a difference between
and is detected up to . Also, about 10\%
of the quenched galaxies in our sample are located between two and four virial
radii () of the massive halos. The median projected distance from
low-mass QGs to their massive neighbors, , decreases with
satellite M* at , but increases with satellite M*
at . This trend suggests a smooth, if any,
transition of the quenching timescale around at
.Comment: 8 pages, 5 figures. ApJL accepted. Typos correcte
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