7124426
Color and Variability Characteristics of Point Sources in the Faint Sky Variability Survey
We present an analysis of the color and variability characteristics for point sources in the Faint Sky Variability Survey (FSVS). The FSVS cataloged ~23 deg2 in BVI filters from ~16 to 24 mag to investigate variability in faint sources at moderate-to-high Galactic latitudes. Point-source completeness is found to be >83% for a selected representative sample (V = 17.5-22.0 mag, B - V = 0.0-1.5) containing both photometric B, V detections and 80% of the time-sampled V data available compared to a basic internal source completeness of 99%. Multiepoch (10-30) observations in V spanning minutes to years modeled by light-curve simulations reveal amplitude sensitivities to ~0.015-0.075 mag over a representative V = 18-22 mag range. Periodicity determinations appear viable to timescales of order 1 day or less using the most sampled fields (~30 epochs). The fraction of point sources is found to be generally variable at 5%-8% over V = 17.5-22.0 mag. For V brighter than 19 mag, the variable population is dominated by low-amplitude (<0.05 mag) and blue (B - V < 0.35) sources, possibly representing a population of γ Doradus stars. Overall, the dominant population of variable sources are bluer than B - V = 0.65 and have main-sequence colors, likely reflecting larger populations of RR Lyrae, SX Phe, γ Doradus, and W UMa variables.
119212613
PUSHING THE BOUNDARIES OF CONVENTIONAL CORE-COLLAPSE SUPERNOVAE: THE EXTREMELY ENERGETIC SUPERNOVA SN 2003ma
We report the discovery of a supernova (SN) with the highest apparent energy output to date and conclude that it represents an extreme example of the Type IIn subclass. The SN, which was discovered behind the Large Magellanic Cloud at z = 0.289 by the SuperMACHO microlensing survey, peaked at MR = –21.5 mag and only declined by 2.9 mag over 4.7 years after the peak. Over this period, SN 2003ma had an integrated bolometric luminosity of 4 × 1051 erg, more than any other SN to date. The radiated energy is close to the limit allowed by conventional core-collapse explosions. Optical spectra reveal that SN 2003ma has persistent single-peaked intermediate-width hydrogen lines, a signature of interaction between the SN and a dense circumstellar medium. The light curves show further evidence for circumstellar interaction, including a long plateau with a shape very similar to the classic SN IIn 1988Z—however, SN 2003ma is 10 times more luminous at all epochs. The fast velocity measured for the intermediate-width Hα component (~6000 km s–1) points toward an extremely energetic explosion (>1052 erg), which imparts a faster blast-wave speed to the post-shock material and a higher luminosity from the interaction than is observed in typical SNe IIn. Mid-infrared observations of SN 2003ma suggest an infrared light echo is produced by normal interstellar dust at a distance ~0.5 pc from the SN.
11448200
The Faint Sky Variability Survey — I. Goals and data reduction process
The Faint Sky Variability Survey is aimed at finding photometric and/or astrometric variable objects in the brightness range between ∼16th and ∼24th mag on time-scales between tens of minutes and years with photometric precisions ranging from 3 millimag for the brightest to 0.2 mag for the faintest objects. An area of ∼23 deg 2 , located at mid and high Galactic latitudes, has been covered using the Wide Field Camera on the 2.5-m Isaac Newton Telescope on La Palma. Here we describe the main goals of the Faint Sky Variability Survey and the data reduction process.
118653047
Ultraluminous supernovae as a new probe of the interstellar medium in distant galaxies
We present the Pan-STARRS1 discovery and light curves, and follow-up MMT and Gemini spectroscopy of an ultra-luminous supernova (ULSN; dubbed PS1-11bam) at a redshift of z = 1.566 with a peak brightness of MUV ≈ -22.3 mag. PS1-11bam is one of the highest redshift spectroscopically-confirmed SNe known to date. The spectrum is characterized by broad absorption features typical of previous ULSNe (e.g., C II, Si III), and by strong and narrow Mg II and Fe II absorption lines from the interstellar medium (ISM) of the host galaxy, confirmed by an [O II]�3727 emission line at the same redshift. The equivalent widths of the Fe II�2600 and Mg II�2803 lines are in the top quartile of the quasar intervening a bsorption system distribution, but are weaker than those of gamma-ray burst intrinsic absorbers (i.e., GR B host galaxies). We also detect the host galaxy in pre-explosion Pan-STARRS1 data and find that its UV spectral energy distribution is best fit with a young stellar population age of �∗ ≈ 15 - 45 Myr and a stellar mass of M∗ ≈ (1.1 - 2.6)× 10 9 M⊙ (for Z = 0.05 - 1 Z⊙). The star formation rate inferred from the UV continuum and [O II]�3727 emission line is ≈ 10 M⊙ yr -1 , higher than in any previous ULSN host. PS1-11bam provides the first direct demonstration that ULSNe can serve as probes of the interstellar medium in distant galaxi es. At the present, the depth and red sensitivity of PS1 are uniquely suited to finding such events at cosmologica lly interesting redshifts ( z ∼ 1 - 2); the future combination of LSST and 30-m class telescopes promises to extend this technique to z ∼ 4.
16396917
Discovery of two new faint cataclysmic variables
We report on the discovery of two new faint cataclysmic variables. The objects were selected as candidates from two different imaging surveys aimed at the discovery of such faint systems. One survey used color and variability while the other used color and Ha emission as selection criteria. We present our spectra of the two new variables and discuss their properties. A discussion of the implication of these discoveries on the space density of faint cataclysmic variables is presented.
15407865
Light Curves of Type Ia Supernovae from Near the Time of Explosion
We present a set of 11 Type Ia supernova (SN Ia) light curves with dense, premaximum sampling. These supernovae (SNe), in galaxies behind the Large Magellanic Cloud (LMC), were discovered by the SuperMACHO survey. The SNe span a redshift range of z = 0.11-0.35. Our light curves contain some of the earliest premaximum observations of SNe Ia to date. We also give a functional model that describes the SN Ia light-curve shape (in our VR band). Our function uses the "expanding fireball" model of Goldhaber et al. to describe the rising light curve immediately after explosion but constrains it to smoothly join the remainder of the light curve. We fit this model to a composite observed VR-band light curve of three SNe between redshifts of 0.135 and 0.165. These SNe have not been K-corrected or adjusted to account for reddening. In this redshift range, the observed VR band most closely matches the rest-frame V band. Using the best fit to our functional description of the light curve, we find the time between explosion and observed VR-band maximum to be 17.6 ± 1.3(stat) ± 0.07(sys) rest-frame days for a SN Ia with a VR-band Δm-10 of 0.52 mag. For the redshifts sampled, the observed VR-band time of maximum brightness should be the same as the rest-frame V-band maximum to within 1.1 rest-frame days.
118463320
Infrared analysis of Dyson-Schwinger equations taking into account the Gribov horizon in Landau gauge
The low momentum behavior of the Landau gauge Gribov-Zwanziger action is investigated using the respective Dyson-Schwinger equations. Because of the mixing of the gluon and the auxiliary fields four scenarios can be distinguished for the infrared behavior. Two of them lead to inconsistencies and can be discarded. Another one corresponds to the case where the auxiliary fields behave exactly like the Faddeev-Popov ghosts and the same scaling relation as in standard Landau gauge, {kappa}{sub A}+2{kappa}{sub c}=0, is valid. Even the parameter {kappa} is found to be the same, 0.595. The mixed propagators, which appear, are suppressed in all loops, and their anomalous infrared exponent can also be determined. A fourth case provides an even stricter scaling relation that includes also the mixed propagators, but possesses the same qualitative feature, i.e. the propagators of the Faddeev-Popov ghost and the auxiliary fields are infrared enhanced and the mixed and the gluon propagators are infrared suppressed. In this case the system of equations to obtain the parameter {kappa} is nonlinear in all variables.
35488270
Search for inelastic dark matter with the CDMS II experiment
Results are presented from a reanalysis of the entire five-tower data set acquired with the Cryogenic Dark Matter Search (CDMS II) experiment at the Soudan Underground Laboratory, with an exposure of 969 kg-days. The analysis window was extended to a recoil energy of 150 keV, and an improved surface-event background-rejection cut was defined to increase the sensitivity of the experiment to the inelastic dark matter (iDM) model. Three dark matter candidates were found between 25 keV and 150 keV. The probability to observe three or more background events in this energy range is 11%. Because of the occurrence of these events, the constraints on the iDM parameter space are slightly less stringent than those from our previous analysis, which used an energy window of 10-100 keV. © 2011 American Physical Society.
120003138
Pion production in nuclear collisions
The production of pions in nuclear collisions is analyzed in terms of a microscopic reaction model, where the free energy of the entrance channel is transferred to the final channel through the coupling of the relative motion to the internal excitation of N*-resonances. Such a model allows quite naturally for a consistent analysis of the exclusive and the inclusive production of pions. It turns out that the pionic fusion cross section is determined predominantly by the spectroscopic parentage between the initial target projectile combination and the final nucleus, whereas the inclusive part is dominated by the energy dependence of the phase space factor, i.e. by the number of the degrees of freedom which are relevant in a given kinematical situation. This model is applied to the analysis of available experimental data from threshold to the Δ(1232)-region. A consistent analysis of both the inclusive and the exclusive part of the pion spectrum is presented.
35420292
The Cryogenic Dark Matter Search test stand warm electronics card
A card which does the signal processing for four SQUID amplifiers and two charge sensitive channels is described. The card performs the same functions as is presently done with two custom 9U × 280 mm Eurocard modules, a commercial multichannel VME digitizer, a PCI to GPIB interface, a PCI to VME interface and a custom built linear power supply. By integrating these functions onto a single card and using the power over Ethernet standard, the infrastructure requirements for instrumenting a Cryogenic Dark Matter Search (CDMS) detector test stand are significantly reduced.
52245958
Revealing Bell’s nonlocality for unstable systems in high energy physics
Entanglement and its consequences—in particular the violation of Bell inequalities, which defies our concepts of realism and locality—have been proven to play key roles in Nature by many experiments for various quantum systems. Entanglement can also be found in systems not consisting of ordinary matter and light, i.e. in massive meson–antimeson systems. Bell inequalities have been discussed for these systems, but up to date no direct experimental test to conclusively exclude local realism was found. This mainly stems from the fact that one only has access to a restricted class of observables and that these systems are also decaying. In this Letter we put forward a Bell inequality for unstable systems which can be tested at accelerator facilities with current technology. Herewith, the long awaited proof that such systems at different energy scales can reveal the sophisticated “dynamical” nonlocal feature of Nature in a direct experiment gets feasible. Moreover, the role of entanglement and $\mathcal{CP}$ violation, an asymmetry between matter and antimatter, is explored, a special feature offered only by these meson–antimeson systems.