Infrared studies of supernova remnants with the IRAS

A comparative study of the infrared and X-ray fluxes and morphologies of supernova remnants (SNR) can yield valuable information on their evolution and on their interaction with the smbient interstellar medium (ISM)

Chandra observations of SN 1987A: the soft X-ray light curve revisited

We report on the present stage of SN 1987A as observed by the Chandra X-ray Observatory. We reanalyze published Chandra observations and add three more epochs of Chandra data to get a consistent picture of the evolution of the X-ray fluxes in several energy bands. We discuss the implications of several calibration issues for Chandra data. Using the most recent Chandra calibration files, we find that the 0.5-2.0 keV band fluxes of SN 1987A have increased by ~6 x 10 ^-13 erg s^-1 cm^-2 per year since 2009. This is in contrast with our previous result that the 0.5-2.0 keV light curve showed a sudden flattening in 2009. Based on our new analysis, we conclude that the forward shock is still in full interaction with the equatorial ring.Comment: Accepted for publication by ApJ, 7 pages, 5 figure

MRI for the evaluation of pectus excavatum

Pectus excavatum, the most common congenital deformity of the anterior chest wall, is both a cosmetic and functional abnormality. The degree of abnormal chest wall deformity determines its functional effect, particularly its cardiac and pulmonary impact. Although CT scanning is the most widely used cross-sectional imaging technique used to measure the Haller index, the radiation exposure is reason to seek other alternatives. At our institution, we have introduced a rapid MRI technique for this purpose, which utilizes a single-axial 2-D FIESTA acquisition

The Resolved Near-Infrared Extragalactic Background

We present a current best estimate of the integrated near-infrared (NIR) extragalactic background light (EBL) attributable to resolved galaxies in J, H, and Ks. Our results in units of nW m-2 sr-1 are 11.7+5.6 -2.6 in J, 11.5+4.5 -1.5 in H and 10.0+2.8 -0.8 in Ks. We derive these new limits by combining our deep wide-field NIR photometry from five widely separated fields with other studies from the literature to create a galaxy counts sample that is highly complete and has good counting statistics out to JHKs ~ 27-28. As part of this effort we present new ultradeep Ks-band galaxy counts from 22 hours of observations with the Multi Object Infrared Camera and Spectrograph (MOIRCS) instrument on the Subaru Telescope. We use this MOIRCS Ks-band mosaic to estimate the total missing flux from sources beyond our detection limits. Our new limits to the NIR EBL are in basic agreement with, but 10 - 20% higher than previous estimates, bringing them into better agreement with estimates of the total NIR EBL (resolved + unresolved sources) obtained from TeV gamma-ray opacity measurements and recent direct measurements of the total NIR EBL. We examine field to field variations in our photometry to show that the integrated light from galaxies is isotropic to within uncertainties, consistent with the expected large-scale isotropy of the EBL. Our data also allow for a robust estimate of the NIR light from Galactic stars, which we find to be 14.7 +/- 2.4 in J, 10.1 +/- 1.9 in H and 7.6 +/- 1.8 in Ks in units of nW m-2 sr-1.Comment: Accepted to Ap

Examining Chemotherapy-Related Cognitive Changes in Colorectal Cancer Patients: A Feasibility Trial

Introduction: Research suggests that chemotherapy may be related to decline in patients’ cognitive functions. Objectives: To assess the feasibility and acceptability of a multi-site study designed to examine the nature and extent of chemotherapy-related cognitive changes in colorectal cancer patients. Method: Data was collected over 8 months using objective and self-reported measures of cognitive functioning and self-reported quality of life, fatigue and mood questionnaires. The assessment battery was administered pre- and mid-chemotherapy treatment to a consecutive sample of colorectal cancer patients across three Londonbased NHS Trusts. Participants included patients who had undergone colorectal surgery and were scheduled to have adjuvant chemotherapy treatment, or no further cancer treatment. Main outcome measures: Recruitment procedures, rate of recruitment, suitability of exclusion/inclusion criteria, acceptability of data collection procedures and the battery, and attrition rates. Results: From 1 April 2014 to 1 December 2014, 42 eligible participants were invited to take part in the trial. Of the 17 that completed pre-chemotherapy assessments, only 1 withdrew at follow-up due to reasons of ill health from disease recurrence. All participants completed the entire battery and indicated that they found the trial acceptable. Conclusions: What went wrong: Strained researcher resources; loss of eligible participants to competing studies, restrictive upper age limit. Possible solutions: Removal of upper age limit, an increased dedicated research team to increase rate of recruitment. The large multi-site study is feasible with suggested amendments and is acceptable to patients and medical teams. Acceptability of trial to medical teams is further evidenced by requests of collaboration from two additional London based NHS Trusts. Lessons learned: This feasibility trial provides evidence to other researchers designing similar studies in this area of an acceptable design and the need for appropriate funding for resources to recruit large enough consecutive samples of patients with solid tumour cancers

A Near-Infrared Spectrometer to Measure Zodiacal Light Absorption Spectrum

We have developed a high throughput infrared spectrometer for zodiacal light fraunhofer lines measurements. The instrument is based on a cryogenic dual silicon Fabry-Perot etalon which is designed to achieve high signal to noise Fraunhofer line profile measurements. Very large aperture silicon Fabry-Perot etalons and fast camera optics make these measurements possible. The results of the absorption line profile measurements will provide a model free measure of the zodiacal Light intensity in the near infrared. The knowledge of the zodiacal light brightness is crucial for accurate subtraction of zodiacal light foreground for accurate measure of the extragalactic background light after the subtraction of zodiacal light foreground. We present the final design of the instrument and the first results of its performance

Dust and the type II-Plateau supernova 2004dj

We present mid-infrared (MIR) spectroscopy of a Type II-plateau supernova, SN 2004dj, obtained with the Spitzer Space Telescope, spanning 106--1393 d after explosion. MIR photometry plus optical/near-IR observations are also reported. An early-time MIR excess is attributed to emission from non-silicate dust formed within a cool dense shell (CDS). Most of the CDS dust condensed between 50 d and 165 d, reaching a mass of 0.3 x 10^{-5} Msun. Throughout the observations much of the longer wavelength (>10 microns) part of the continuum is explained as an IR echo from interstellar dust. The MIR excess strengthened at later times. We show that this was due to thermal emission from warm, non-silicate dust formed in the ejecta. Using optical/near-IR line-profiles and the MIR continua, we show that the dust was distributed as a disk whose radius appeared to be slowly shrinking. The disk radius may correspond to a grain destruction zone caused by a reverse shock which also heated the dust. The dust-disk lay nearly face-on, had high opacities in the optical/near-IR regions, but remained optically thin in the MIR over much of the period studied. Assuming a uniform dust density, the ejecta dust mass by 996 d was 0.5 +/- 0.1) x 10^{-4} Msun, and exceeded 10^{-4}Msun by 1393 d. For a dust density rising toward the center the limit is higher. Nevertheless, this study suggests that the amount of freshly-synthesized dust in the SN 2004dj ejecta is consistent with that found from previous studies, and adds further weight to the claim that such events could not have been major contributors to the cosmic dust budget.Comment: ApJ in press; minor changes c.f. v