Several accurate analyses have revealed a statistically significant North-South ecliptic asymmetry in the large-angle correlations strength of the Cosmic Microwave Background (CMB) radiation temperature field data from the Wilkinson Microwave Anisotropy Probe (WMAP). This asymmetry is inconsistent with the statistical isotropy expected in the concordance cosmological model LCDM. It has been suggested that a possible cause-effect relationship exists between this large-angle anisotropy and the anomalous CMB quadrupole-octopole planes alignment. In turn, this later phenomenon (or both) would be a consequence of one or more of the following undesired effects in CMB data: a systematic error in the data processing or in the instrument characterization, residual foregrounds, and large-angle correlations induced by the incomplete sky CMB data (cut-sky masks are needed to reject Galactic foregrounds). Here, it is proved that the North-South (NS) asymmetry is unrelated to the quadrupole (l=2) and the octopole (l=3) properties because we find, at high confidence levels, such large-angle anisotropy in three- and five-year WMAP CMB maps containing only the multipole components 4 <= l <= 10. The statistical significance depends on both, the CMB map analyzed as well as the cut-sky mask applied to exclude foregrounds. The significance level of the NS-asymmetry is less in five-year WMAP data with KQ75 (> 90% CL) than it is in three-year data with Kp0 (> 96% CL). Additionally, robustness tests show that the statistical significance of the NS-asymmetry is affected by the use of the KQ85 and KQ75 masks in five-year single-frequency WMAP CMB maps, whereas it is insensitive with respect to application of the Kp2 and Kp0 masks in three-year single-frequency WMAP CMB maps.
South Pole Station offers a unique combination of high, dry, stable conditions and well-developed support facilities. Over the past 20 years, a sequence of increasingly sophisticated CMB experiments at Pole have built on the experience of early pioneering efforts, producing a number of landmark contributions to the field. Telescopes at the South Pole were among the first to make repeated detections of degree-scale CMB temperature anisotropy and to map out the harmonic structure of its acoustic peaks. More recent achievements include the first detection of polarization of the CMB and the most p…
In this paper, we investigate the spatial distribution of solar flares in the northern and southern hemisphere of the Sun that occurred during the period 1996 to 2003. This period of investigation includes the ascending phase, the maximum and part of descending phase of solar cycle 23. It is revealed that the flare activity during this cycle is low compared to previous solar cycle, indicating the violation of Gnevyshev-Ohl rule. The distribution of flares with respect to heliographic latitudes shows a significant asymmetry between northern and southern hemisphere which is maximum during the mi…
Photometric redshifts have been calculated for the Hubble Deep Fields. The redshift distributions of the fields differ; there is a large excess of galaxies in the HDF-North in the redshift range 0.4<z<1.2. The difference is consistent with the presence of a weak cluster in the HDFN and is only slightly larger than the cosmic variance in other fields of similar depths and with models of large scale structure.
In this paper, we have made a statistical analysis of solar H$α$ flares that occurred during the period 1996 to 2005 to investigate their spatial distribution with respect to northern and southern hemispheres of the Sun. The analysis includes a total of 21608 single events. The study shows a significant N$-$S asymmetry which is persistent with the evolution of the solar cycle. The flare activity favors the northern hemisphere in general during the rising and maximum phase of the solar cycle (i.e., in 1997, 1999, and 2000), while the declining phase (i.e., from 2001 to 2005) shows a southern do…
We present a correlation between the ACME/SP94 CMB anisotropy data at 25 to 45 GHz with the IRAS/DIRBE data and the Haslam 408 MHz data. We find a marginal correlation between the dust and the Q-band CMB data but none between the CMB data and the Haslam map. While the amplitude of the correlation with the dust is larger than that expected from naive models of dust emission it does not dominate the sky emission.
We compare the large scale galaxy clustering between the North and South SDSS early data release (EDR) and also with the clustering in the APM Galaxy Survey. The three samples are independent and cover an area of 150, 230 and 4300 square degrees respectively. We combine SDSS data in different ways to approach the APM selection. Given the good photometric calibration of the SDSS data and the very good match of its North and South number counts, we combine them in a single sample. The joint clustering is compared with equivalent subsamples in the APM. The final sampling errors are small enough t…
We perform a series of two-dimensional magnetohydrodynamic simulations of supernova cores. Since the distributions of the angular momentum and the magnetic fields of strongly magnetized stars are quite uncertain, we systematically change the combinations of the strength of the angular momentum, the rotations law, the degree of differential rotation, and the profiles of the magnetic fields to construct the initial conditions. By so doing, we estimate how the rotation-induced anisotropic neutrino heating are affected by the strong magnetic fields through parity-violating effects and first invest…
In this paper the N-S asymmetry of the soft X-ray flare index during the solar cycles 21, 22 and 23 has been analyzed. The results show the existence of a real N-S asymmetry which is strengthened during solar minimum. The slope of the regression lines fitted to the daily values of asymmetry time series has been found to be negative in all the three cycles. The yearly asymmetry curve can be fitted by a sinusoidal function with a period of eleven years. The power spectral analysis of daily asymmetry time series reveals the significant periods of around 28.26 days, 550.73 days and 3.72 years.
Using Greenwich and SOON sunspot group data during the period 1874 -- 2005, we find that the sums of the areas of the sunspot groups in $0^\circ$ -- $10^\circ$ latitude-interval of the Sun's northern hemisphere and in the time-interval, minus 1.35 year to plus 2.15 year from the time of the preceding minimum--and in the same latitude interval of the southern hemisphere but plus 1.0 year to plus 1.75 year from the time of the maximum--of a sunspot cycle are well correlating with the amplitude (maximum of the smoothed monthly sunspot number) of its immediate following cycle. Using this relations…
We present results of near infrared imaging of the disk-galaxy-merger NGC 6240 using adaptive optics on the Keck II Telescope and reprocessed archival data from NICMOS on the Hubble Space Telescope. Both the North and South nuclei of NGC 6240 are clearly elongated, with considerable sub-structure within each nucleus. In K' band there are at least two point-sources within the North nucleus; we tentatively identify the south-western point-source within the North nucleus as the position of one of the two AGNs. Within the South nucleus, the northern sub-nucleus is more highly reddened. Based upon …
Based on drizzled F606W and F814W images, we present quantitative structural parameters in the V-band rest-frame for all galaxies with z<1 and I_814(AB)<24.5 mag in the Hubble Deep Fields North and South. Our structural parameters are based on a two-component surface brightness distribution using a Sersic bulge and an exponential disc. Detailed simulations and comparisons with previous work are presented. The luminosity-size distribution of early-type galaxies is consistent with the hypothesis that their structural properties were already in place by z~1 and have evolved passively since then; …
We develop a method of constraining the cosmic string tension $Gμ$ which uses the Canny edge detection algorithm as a means of searching CMB temperature maps for the signature of the Kaiser-Stebbins effect. We test the potential of this method using high resolution, simulated CMB temperature maps. By modeling the future output from the South Pole Telescope project (including anticipated instrumental noise), we find that cosmic strings with $Gμ> 5.5\times10^{-8}$ could be detected.
We use combinations of ten small-scale cosmic microwave background anisotropy data sets from the UCSB South Pole 1994, ARGO, MAX 4 and 5, White Dish and SuZIE experiments to constrain cosmogonies. We consider open and spatially-flat-Lambda cold dark matter cosmogonies. Marginalizing over all parameters but $Ω_0$, the combined data favors an Omega_0 simeq 1 for both open and flat-Lambda models. Excluding the smallest angular scale SuZIE data, an Omega_0 simeq 0.3 (1.0) open (flat-Lambda) model is favored. Considering only multi-frequency data with error bars consistent with sample variance and …
The frequency of barred spiral galaxies as a function of redshift contains important information on the gravitational influence of stellar disks in their dark matter halos and also may distinguish between contemporary theories for the origin of galactic bulges. In this paper we present a new quantitative method for determining the strength of barred spiral structure, and verify its robustness to redshift-dependent effects. By combining galaxy samples from the Hubble Deep Field North with newly available data from the Hubble Deep Field South, we are able to define a statistical sample of 18 obj…
We use joint likelihood analyses of combinations of fifteen cosmic microwave background (CMB) anisotropy data sets from the DMR, UCSB South Pole 1994, Python I--III, ARGO, MAX 4 and 5, White Dish, OVRO, and SuZIE experiments to constrain cosmogonies. We consider open and spatially-flat-Lambda cold dark matter cosmogonies, with nonrelativistic-mass density parameter Omega_0 in the range 0.1--1, baryonic-mass density parameter Omega_B in the range (0.005--0.029) h^{-2}, and age of the universe t_0 in the range (10--20) Gyr. Marginalizing over all parameters but Omega_0, the data favor Omega_0 \s…
We develop methods to account for experimental and observational uncertainties in likelihood analyses of data from cosmic microwave background (CMB) anisotropy experiments and apply them to an analysis of the UCSB South Pole 1994 (SP94) experiment. Observationally motivated open and spatially-flat $Λ$, cold dark matter cosmogonies are considered. Among the models we consider, the full SP94 data set is most consistent with $Ω_0 \sim 0.1-0.2$ open models and less so with old $(t_0 \gap 15 - 16 Gyr)$, high baryon density $(Ω_B \gap 0.0175 h^{-2})$, low density ($Ω_0 \sim 0.2 - 0.4), flat-$Λ$ mode…
We present a statistical study of the presence of galaxy warps in the Hubble deep fields. Among a complete sample of 45 edge-on galaxies above a diameter of 1.''3, we find 5 galaxies to be certainly warped and 6 galaxies as good candidates. In addition, 4 galaxies reveal a characteristic U-warp. Compared to statistical studies of local warps, and taking into account the strong bias against observing the outer parts of galaxies at high redshift, these numbers point towards a very high frequency of warps at z \sim 1: almost all galaxy discs might be warped. Furthermore, the amplitude of warps ar…
We investigate the dispersion in the internal colours of faint spheroidals in the HDFs North and South. We find that a remarkably large fraction ~30% of the morphologically classified spheroidals with I<24 mag show strong variations in internal colour, which we take as evidence for recent episodes of star-formation. In most cases these colour variations manifest themselves via the presence of blue cores, an effect of opposite sign to that expected from metallicity gradients. Examining similarly-selected ellipticals in five rich clusters with 0.37<z<0.83 we find a significant lower dispersion i…
The Faulkes Telescope Project is the educational arm of the Las Cumbres Observatory Global Telescope Network (LCOGT). It currently has two 2-metre robotic telescopes, located at Haleakala on Maui (FT North) and Siding Spring in Australia (FT South). It is planned to increase this to six 2-metre telescopes in the future, complemented by a network of 30-40 smaller (0.4-1 metre) telescopes providing 24 hour coverage of both northern and southern hemispheres. We are undertaking a study of 10 low-mass X-ray binaries (LMXBs) using FT North to study the optical continuum behaviour of X-ray transients…
Observation of the CMB is central to observational cosmology, and the Antarctic Plateau is an exceptionally good site for this work. The first attempt at CMB observations from the Plateau was an expedition to the South Pole in December 1986 by the Radio Physics Research group at Bell Laboratories. Sky noise and opacity were measured. The results were sufficiently encouraging that in the Austral summer of 1988-1989, three CMB groups participated in the "Cucumber" campaign, where a temporary site dedicated to CMB anisotropy measurements was set up 2 km from South Pole Station. Winter-time observ…
We apply spherical needlets to the Wilkinson Microwave Anisotropy Probe 5-year cosmic microwave background (CMB) dataset, to search for imprints of non-isotropic features in the CMB sky. We use the needlets localization properties to resolve peculiar features in the CMB sky and to study how these features contribute to the anisotropy power spectrum of the CMB. In addition to the now well-known "cold spot" of the CMB map in the southern hemisphere, we also find two hot spots at greater than 99% confidence level, again in the southern hemisphere and closer to the Galactic plane. While the cold s…
The halo structure at high Galactic latitudes near both the north and south poles is studied using SDSS and SuperCOSMOS data. For the south cap halo, the archive of the SuperCOSMOS photographic photometry sky survey is used. The coincident source rate between SuperCOSMOS data in $B_J$ band from $16^m.5$ to $20^m.5$ and SDSS data is about 92%, in a common sky area in the south. While that in the $R_F$ band is about 85% from $16^m.5$ to $19^m.5$. Transformed to the SuperCOSMOS system and downgraded to the limiting magnitudes of SuperCOSMOS, the star counts in the northern Galactic cap from SDSS …
Several accurate analyses of the CMB temperature maps from the Wilkinson Microwave Anisotropy Probe (WMAP) have revealed a set of anomalous results, at large angular scales, that appears inconsistent with the statistical isotropy expected in the concordance cosmological model $Λ$CDM. Because these anomalies seem to indicate a preferred direction in the space, here we investigate the signatures that a primordial magnetic field, possibly present in the photon-baryon fluid during the decoupling era, could have produced in the large-angle modes of the observed CMB temperature fluctuations maps. To…
