Early-type Host Galaxies of Type Ia Supernovae. I. Evidence for Downsizing

Type Ia supernova (SN Ia) cosmology provides the most direct evidence for the presence of dark energy. This result is based on the assumption that the look-back time evolution of SN Ia luminosity, after light-curve corrections, would be negligible. Recent studies show, however, that the Hubble residual (HR) of SN Ia is correlated with the mass and morphology of host galaxies, implying the possible dependence of SN Ia luminosity on host galaxy properties. In order to investigate this more directly, we have initiated spectroscopic survey for the early-type host galaxies, for which population age and metallicity can be more reliably determined from the absorption lines. As the first paper of the series, here we present the results from high signal-to-noise ratio (>100 per pixel) spectra for 27 nearby host galaxies in the southern hemisphere. For the first time in host galaxy studies, we find a significant (~3.9sigma) correlation between host galaxy mass (velocity dispersion) and population age, which is consistent with the "downsizing" trend among non-host early-type galaxies. This result is rather insensitive to the choice of population synthesis models. Since we find no correlation with metallicity, our result suggests that stellar population age is mainly responsible for the relation between host mass and HR. If confirmed, this would imply that the luminosity evolution plays a major role in the systematic uncertainties of SN Ia cosmology.Comment: Accepted for publication in ApJ

Environmental Dependence of Type Ia Supernova Luminosities from a Sample without a Local-Global Difference in Host Star Formation

It is now established that there is a dependence of the luminosity of type Ia supernovae (SNe Ia) on environment: SNe Ia in young, star-forming, metal-poor stellar populations appear fainter after light-curve shape corrections than those in older, passive, metal-rich environments. This is accounted for in cosmological studies using a global property of the SN host galaxy, typically the host galaxy stellar mass. However, recent low-redshift studies suggest that this effect manifests itself most strongly when using the local star-formation rate (SFR) at the SN location, rather than the global SFR or stellar mass of the host galaxy. At high-redshift, such local SFRs are difficult to determine; here, we show that an equivalent 'local' correction can be made by restricting the SN Ia sample in globally star-forming host galaxies to a low-mass host galaxy subset ($\le10^{10} M_{\odot}$). Comparing this sample of SNe Ia (in locally star-forming environments) to those in locally passive host galaxies, we find that SNe Ia in locally star-forming environments are $0.081\pm0.018$ mag fainter ($4.5\sigma$), consistent with the result reported by Rigault et al. (2015), but our conclusion is based on a sample ~5 times larger over a wider redshift range. This is a larger difference than when splitting the SN Ia sample based on global host galaxy SFR or host galaxy stellar mass. This method can be used in ongoing and future high-redshift SN surveys, where local SN Ia environments are difficult to determine.Comment: 16 pages, 3 figures, and 5 tables, accepted for publication in Ap

Heisenberg-picture approach to the exact quantum motion of a time-dependent forced harmonic oscillator

In the Heisenberg picture, the generalized invariant and exact quantum motions are found for a time-dependent forced harmonic oscillator. We find the eigenstate and the coherent state of the invariant and show that the dispersions of these quantum states do not depend on the external force. Our formalism is applied to several interesting cases.Comment: 15 pages, two eps files, to appear in Phys. Rev. A 53 (6) (1996

Reconsidering photometric estimation of local star formation environment and its correlation with Type Ia Supernova luminosity

Recent studies on the environmental dependence of Type Ia supernova (SN Ia) luminosity focus on the local environment where the SN exploded, considering that this is more directly linked to the SN progenitors. However, there is a debate about the local environmental, specifically local star formation rate (SFR), dependence of the SN Ia luminosity. A recent study claims that the dependence is insignificant ($0.051 \pm 0.020$ mag; $2.6\sigma$), based on the local SFR measurement by fitting local $ugrizy$ photometry data. However, we find that this photometric local SFR measurement is inaccurate. We argue this based on the theoretical background of SFR measurement and the methodology used to make that claim with their local $ugrizy$ photometry data, especially due to a limited range of extinction parameters used when fitting the data. Therefore, we re-analyse the same host galaxies with the same fitting code, but with more physically motivated extinction treatments and global $ugriz$ photometry of host galaxies. We estimate global stellar mass and SFR. Then, local star formation environments are inferred by using the method which showed that SNe Ia in globally passive galaxies have locally passive environments, while those in globally star-forming low-mass galaxies have locally star-forming environments. We find that there is significant local environmental dependence of SN Ia luminosities: SNe Ia in locally star-forming environments are $0.072\pm0.021$ mag ($3.4\sigma$) fainter than those in locally passive environments, even though SN Ia luminosities have been further corrected by the BBC method that reduces the size of the dependence.Comment: 10 pages, 7 figures, 3 tables and 1 appendix table containing data we used; accepted for publication in MNRA

Macular Infarction Associated with Reactive Arthritis

A 53-year-old woman visited the Department of Rheumatology with a chief complaint of a 3-day history of fever and chills and also presented with pain occuring in both knees at the time of outpatient visit. Based on rheumatologic and hematological lab studies, ultrasonography, and a needle aspiration biopsy of the articular cavity, the patient was diagnosed with reactive arthritis. On hospitalization day 3, consultation with the Department of Ophthalmology was requested regarding decreased visual acuity lasting for 3 days. Upon ophthalmologic examination, the corrected visual acuity was 0.1 in the right eye and 0.05 in the left eye. Upon slit lamp microscopy, there were no abnormal findings in the anterior segment. Upon fundus examination, however, there were yellow-white lesions in the macular area of both eyes. Fluorescein angiographywas performed to assess the macular lesions, and the findings were suggestive of macular infarction in both eyes. Due to a lack of other underlying disease, a past surgical history, and a past history of drug administration, the patient was diagnosed with macular infarction in both eyes associated with reactive arthritis. To date, there have been no other such cases reported. In a patient with reactive arthritis, we experienced a case of macular infarction in both eyes, which occurred without association with a past history of specific drug use or underlying disease. Herein, we report our case, with a review of the literature

Adrenalectomy for Metastatic Disease to the Adrenal Gland from Gastric Cancer: Report of a Case

Metastases to the adrenal glands are frequently found at autopsy. In practice, adrenal metastases have generally been accepted as evidence of blood-borne systemic disease. So, clinically curable adrenal metastases is a rare malady. The role for surgical resection in adrenal metastases has not been clearly defined. A 45-year-old man initially underwent total gastrectomy with D2 lymph node dissection for treating his advanced gastric cancer. A solitary adrenal metastases was resected 1 year later. The patient has survived for 3 years and no further evidence of disease was found on his last follow-up examination. We report here on this case to show that for selected cases, surgical resection of adrenal metastases is feasible and this procedure may extend survival for metastatic gastric cancer patients

Shor-Preskill Type Security-Proofs for Concatenated Bennett-Brassard 1984 Quantum Key Distribution Protocol

We discuss long code problems in the Bennett-Brassard 1984 (BB84) quantum key distribution protocol and describe how they can be overcome by concatenation of the protocol. Observing that concatenated modified Lo-Chau protocol finally reduces to the concatenated BB84 protocol, we give the unconditional security of the concatenated BB84 protocol.Comment: 4 pages, RevTe

Gas distribution, kinematics and star formation in faint dwarf galaxies

We compare the gas distribution, kinematics and the current star formation in a sample of 10 very faint (-13.37 < M_B < -9.55) dwarf galaxies. For 5 of these galaxies we present fresh, high sensitivity, GMRT HI 21cm observations. For all our galaxies we construct maps of the HI column density at a constant linear resolution of ~300 pc; this forms an excellent data set to check for the presence of a threshold column density for star formation. We find that while current star formation (as traced by Halpha emission) is confined to regions with relatively large (N_HI > (0.4 -1.7) X 10^{21} atoms cm^{-2}) HI column density, the morphology of the Halpha emission is in general not correlated with that of the high HI column density gas. Thus, while high column density gas may be necessary for star formation, in this sample at least, it is not sufficient to ensure that star formation does in fact occur. We examine the line profiles of the HI emission, but do not find a simple relation between regions with complex line profiles and those with on-going star formation. Finally, we examine the very fine scale (~20-100 pc) distribution of the HI gas, and find that at these scales the emission exhibits a variety of shell like, clumpy and filamentary features. The Halpha emission is sometimes associated with high density HI clumps, sometimes the Halpha emission lies inside a high density shell, and sometimes there is no correspondence between the Halpha emission and the HI clumps. In summary, the interplay between star formation and gas density in these galaxy does not seem to show the simple large scale patterns observed in brighter galaxies (abridged).Comment: 15 pages, 6 tables, 13 figures. Accepted for publication in MNRA

Improvements in structural and optical properties of wafer-scale hexagonal boron nitride film by post-growth annealing

Remarkable improvements in both structural and optical properties of wafer-scale hexagonal boron nitride (h-BN) films grown by metal-organic chemical vapor deposition (MOCVD) enabled by high-temperature post-growth annealing is presented. The enhanced crystallinity and homogeneity of the MOCVD-grown h-BN films grown at 1050 degrees C is attributed to the solid-state atomic rearrangement during the thermal annealing at 1600 degrees C. In addition, the appearance of the photoluminescence by excitonic transitions as well as enlarged optical band gap were observed for the post-annealed h-BN films as direct consequences of the microstructural improvement. The post-growth annealing is a very promising strategy to overcome limited crystallinity of h-BN films grown by typical MOCVD systems while maintaining their advantage of multiple wafer scalability for practical applications towards two-dimensional electronics and optoelectronics.11Ysciescopu