983 research outputs found

    An imaging gas scintillation proportional counter for the detection of subkiloelectron-volt X-rays

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    A large area imaging gas scintillation proportional counter (IGSPC) was constructed for use in X-ray astronomy. The IGSPC consists of a gas scintillation proportional counted (GSPC) with a micron polyprotylene window coupled to a multiwire proportional counter (MWPC) via a calcium fluoride window. Over a sensitive area of 21 cu cm the instrument has a measured energy resolution of 17.5% (FWHM) and 1.9 mm (FWHM) spatial resolution at 1.5 keV

    CO-Dark Star Formation and Black Hole Activity in 3C 368 at z = 1.131: Coeval Growth of Stellar and Supermassive Black Hole Masses

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    We present the detection of four far-infrared fine-structure oxygen lines, as well as strong upper limits for the CO(2-1) and [N II] 205 um lines, in 3C 368, a well-studied radio-loud galaxy at z = 1.131. These new oxygen lines, taken in conjunction with previously observed neon and carbon fine-structure lines, suggest a powerful active galactic nucleus (AGN), accompanied by vigorous and extended star formation. A starburst dominated by O8 stars, with an age of ~6.5 Myr, provides a good fit to the fine-structure line data. This estimated age of the starburst makes it nearly concurrent with the latest episode of AGN activity, suggesting a link between the growth of the supermassive black hole and stellar population in this source. We do not detect the CO(2-1) line, down to a level twelve times lower than the expected value for star forming galaxies. This lack of CO line emission is consistent with recent star formation activity if the star-forming molecular gas has low metallicity, is highly fractionated (such that CO is photodissociated through much of the clouds), or is chemically very young (such that CO has not yet had time to form). It is also possible, though we argue unlikely, that the ensemble of fine structure lines are emitted from the region heated by the AGN.Comment: 10 pages, 4 figures, 2 tables, accepted for publication in the Astrophysical Journa

    Development of thermally formed glass optics for astronomical hard x-ray telescopes

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    The next major observational advance in hard X-ray/soft gamma-ray astrophysics will come with the implementation of telescopes capable of focusing 10-200 keV radiation. Focusing allows high signal-to-noise imaging and spectroscopic observations of many sources in this band for the first time. The recent development of depth-graded multilayer coatings has made the design of telescopes for this bandpass practical, however the ability to manufacture inexpensive substrates with appropriate surface quality and figure to achieve sub-arcminute performance has remained an elusive goal. In this paper, we report on new, thermally-formed glass micro-sheet optics capable of meeting the requirements of the next-generation of astronomical hard X-ray telescopes

    28522 The impact of the SARS-CoV-2 pandemic on phototherapy utilization

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    Phototherapy is a mainstay of treatment for several dermatologic conditions. Patients often require multiple treatments per week for several weeks to months to achieve treatment efficacy. The SARS-CoV-2 global pandemic caused many dermatology clinics to close completely or significantly reduce patient volumes, which may have limited patient access to this beneficial treatment. This retrospective study examines the pandemic’s impact on phototherapy treatment rates and reimbursement at one major tertiary care center and five locations of a private dermatology clinic in Southeast Michigan. Phototherapy CPT reimbursement data from March 1-June 30, 2020 was compared with the same timeframe in 2019. Units of phototherapy performed decreased by an average of 84%, and there was an average decrease of 43% in the number of unique patients receiving treatments. Reimbursement for phototherapy decreased by an average of 83%. The drastic decline in phototherapy reimbursement is a reflection of the pandemic’s financial impact and likely correlates to a larger scale of revenue loss in dermatology practices. Adequate phototherapy treatment was also likely delayed for many patients. As the pandemic continues, implementation of home phototherapy treatments may be necessary for patients to receive proper treatment and to minimize the impact of loss of revenue due to limited in-office phototherapy. Precautions will need to be taken to guarantee the safety of patients and the care team for patients to receive optimal in-office phototherapy treatment. The pandemic’s impact on medical dermatology finances could potentially destabilize access to patients who need this safe and effective treatment

    Development of Aluminum LEKIDs for Balloon-Borne Far-IR Spectroscopy

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    We are developing lumped-element kinetic inductance detectors (LEKIDs) designed to achieve background-limited sensitivity for far-infrared (FIR) spectroscopy on a stratospheric balloon. The Spectroscopic Terahertz Airborne Receiver for Far-InfraRed Exploration (STARFIRE) will study the evolution of dusty galaxies with observations of the [CII] 158 μ\mum and other atomic fine-structure transitions at z=0.5−1.5z=0.5-1.5, both through direct observations of individual luminous infrared galaxies, and in blind surveys using the technique of line intensity mapping. The spectrometer will require large format (∼\sim1800 detectors) arrays of dual-polarization sensitive detectors with NEPs of 1×10−171 \times 10^{-17} W Hz−1/2^{-1/2}. The low-volume LEKIDs are fabricated with a single layer of aluminum (20 nm thick) deposited on a crystalline silicon wafer, with resonance frequencies of 100−250100-250 MHz. The inductor is a single meander with a linewidth of 0.4 μ\mum, patterned in a grid to absorb optical power in both polarizations. The meander is coupled to a circular waveguide, fed by a conical feedhorn. Initial testing of a small array prototype has demonstrated good yield, and a median NEP of 4×10−184 \times 10^{-18} W Hz−1/2^{-1/2}.Comment: accepted for publication in Journal of Low Temperature Physic
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