Direct Estimate of Cirrus Noise in Herschel Hi-GAL Images

In Herschel images of the Galactic plane and many star forming regions, a major factor limiting our ability to extract faint compact sources is cirrus confusion noise, operationally defined as the "statistical error to be expected in photometric measurements due to confusion in a background of fluctuating surface brightness". The histogram of the flux densities of extracted sources shows a distinctive faint-end cutoff below which the catalog suffers from incompleteness and the flux densities become unreliable. This empirical cutoff should be closely related to the estimated cirrus noise and we show that this is the case. We compute the cirrus noise directly, both on Herschel images from which the bright sources have been removed and on simulated images of cirrus with statistically similar fluctuations. We connect these direct estimates with those from power spectrum analysis, which has been used extensively to predict the cirrus noise and provides insight into how it depends on various statistical properties and photometric operational parameters. We report multi-wavelength power spectra of diffuse Galactic dust emission from Hi-GAL observations at 70 to 500 microns within Galactic plane fields at l= 30 degrees and l= 59 degrees. We find that the exponent of the power spectrum is about -3. At 250 microns, the amplitude of the power spectrum increases roughly as the square of the median brightness of the map and so the expected cirrus noise scales linearly with the median brightness. Generally, the confusion noise will be a worse problem at longer wavelengths, because of the combination of lower angular resolution and the rising power spectrum of cirrus toward lower spatial frequencies, but the photometric signal to noise will also depend on the relative spectral energy distribution of the source compared to the cirrus.Comment: 4 pages (in journal), 3 figures, Astronomy and Astrophysics, accepted for publication 13 May 201

Mapping the column density and dust temperature structure of IRDCs with Herschel

Infrared dark clouds (IRDCs) are cold and dense reservoirs of gas potentially available to form stars. Many of these clouds are likely to be pristine structures representing the initial conditions for star formation. The study presented here aims to construct and analyze accurate column density and dust temperature maps of IRDCs by using the first Herschel data from the Hi-GAL galactic plane survey. These fundamental quantities, are essential for understanding processes such as fragmentation in the early stages of the formation of stars in molecular clouds. We have developed a simple pixel-by-pixel SED fitting method, which accounts for the background emission. By fitting a grey-body function at each position, we recover the spatial variations in both the dust column density and temperature within the IRDCs. This method is applied to a sample of 22 IRDCs exhibiting a range of angular sizes and peak column densities. Our analysis shows that the dust temperature decreases significantly within IRDCs, from background temperatures of 20-30 K to minimum temperatures of 8-15 K within the clouds, showing that dense molecular clouds are not isothermal. Temperature gradients have most likely an important impact on the fragmentation of IRDCs. Local temperature minima are strongly correlated with column density peaks, which in a few cases reach NH2 = 1 x 10^{23} cm^{-2}, identifying these clouds as candidate massive prestellar cores. Applying this technique to the full Hi-GAL data set will provide important constraints on the fragmentation and thermal properties of IRDCs, and help identify hundreds of massive prestellar core candidates.Comment: Accepted for publication in A&A Herschel special issu

Detection of [O I] 63 <i>μ</i>m in absorption toward Sgr B2

A high signal-to-noise 52-90 μm spectrum is presented for the central part of the Sagittarius B2 complex. The data were obtained with the Long Wavelength Spectrometer on board the Infrared Space Observatory (ISO). The [O I] 63 μm line is detected in absorption even at the grating spectral resolution of 0.29 μm. A lower limit for the column density of atomic oxygen of the order of 1019 cm-2 is derived. This implies that more than 40% of the interstellar oxygen must be in atomic form along the line of sight toward the Sgr B2 molecular cloud

Inequity in rehabilitation interventions after hip fracture:a systematic review

Objective To determine the extent to which equity factors contributed to eligibility criteria of trials of rehabilitation interventions after hip fracture. We define equity factors as those that stratify healthcare opportunities and outcomes.Design Systematic search of MEDLINE, Embase, CINHAL, PEDro, Open Grey, BASE, and ClinicalTrials.gov for randomized controlled trials of rehabilitation interventions after hip fracture published between 1st January 2008 and 30th May 2018. Trials not published in English, secondary prevention or new models of service delivery (e.g. orthogeriatric care pathway) were excluded. Duplicate screening for eligibility, risk of bias (Cochrane Risk of Bias Tool), and data extraction (Cochrane’s PROGRESS-Plus framework).Results 23 published, 8 protocol, 4 registered ongoing randomized controlled trials (4,449 participants) were identified. A total of 69 equity factors contributed to eligibility criteria of the 35 trials. For more than 50% of trials, potential participants were excluded based on residency in a nursing home, cognitive impairment, mobility/functional impairment, minimum age, and/or nonsurgical candidacy. Where reported, this equated to the exclusion of 2,383 out of 8,736 (27.3%) potential participants based on equity factors. Residency in a nursing home and cognitive impairment were the main drivers of these exclusions. Conclusion The generalizability of trial results to the underlying population of frail older adults is limited. Yet this is the evidence base underpinning current service design. Future trials should include participants with cognitive impairment and those admitted from nursing homes. For those excluded, an evidence-informed reasoning for the exclusion should be explicitly stated.PROSPERO CRD42018085930<br/

Extended fine structure and continuum emission from S140/L1204

Grating spectra, covering the wavelength range 45 to 187μm have been taken with the ISO Long Wavelength Spectrometer (LWS) at a series of pointing positions over the S 140 region, centred on the cluster of embedded young stellar objects at the south-west corner of the L1204 molecular cloud. Extended emission from [CII]158μm and [OI]63μm is seen, peaking near the position of the embedded stars. The measurements of the fine structure lines are interpreted in terms of PDR models for the emission, as well as the underlying thermal continuum for the heated gas and dust

The ISO LWS grating spectrum of NGC 7027

We present a high signal-to-noise ISO Long Wavelength Spectrometer (LWS) grating spectrum of the planetary nebula NGC 7027 from 43-194μm. In total 40 emission lines have been detected, with 30 identified. From the ionized region, we observe fine-structure lines from [N II], [N III] and [O III]. The [O I] and [C II] fine-structure lines from the photodissociation region are the strongest features observed in this spectral region. Amongst the molecular lines, 11 pure rotation CO lines from J=14-13 up to J=24-23 have been detected. The most striking result, however, is the detection in this carbon-rich nebula of the o-H_2_O 179.53μm and the OH 119.3μm fundamental lines. Astrophysical implications are briefly discussed

Isolated starless cores in IRDCs in the Hi-GAL survey

In a previous paper we identified cores within infrared dark clouds (IRDCs). We regarded those without embedded sources as the least evolved, and labelled them starless. Here we identify the most isolated starless cores and model them using a three-dimensional, multi-wavelength, Monte Carlo, radiative transfer code. We derive the cores' physical parameters and discuss the relation between the mass, temperature, density, size and the surrounding interstellar radiation field (ISRF) for the cores. The masses of the cores were found not to correlate with their radial size or central density. The temperature at the surface of a core was seen to depend almost entirely on the level of the ISRF surrounding the core. No correlation was found between the temperature at the centre of a core and its local ISRF. This was seen to depend, instead, on the density and mass of the core.Comment: 12 pages + appendix, 12 figures, 4 tables. Only a sample of images in Appendix A is given due to size restrictions. Accepted by MNRA

Consensus Statement on the Prevention and Management of Complications of Fully Ablative Laser Resurfacing of the Face

ObjectivesTo achieve consensus among expert laser surgeons on standards for the prevention and management of adverse events from fully ablative laser resurfacing of the face.Materials and methodsDelphi study with two rounds of ratings and revisions until consensus was achieved. The draft set of statements was developed by a steering committee based on expert clinical experience. This was followed by two rounds of rating and revisions completed by an expert panel, then a virtual consensus meeting. In both rounds, respondents rated the draft statements on a 9-point Likert scale (1 = strongly disagree; 9 = strongly agree) and optionally provided comments. The consensus meeting was supplemented by the results of a systematic review of the literature (from 2000 to 2023).ResultsTwo rounds of Delphi survey were completed by 34 participants across four countries. Represented specialties were dermatology, facial plastic surgery, plastic surgery, and oculoplastic surgery. The initial 105 statements from round 1 expanded to 112 in round 2, with 96 statements achieving consensus. These included possible adverse events (11 statements); absolute and relative contraindications to treatment (5 statements); preoperative care and antimicrobial prophylaxis precautions (16 statements); intraoperative precautions (17 statements); postoperative care (21 statements); monitoring for and management of infection (16 statements); management of pigmentation changes (6 statements); and management of scarring and incipient scarring (4 statements).ConclusionAn international consensus statement was developed for the prevention and management of complications associated with fully ablative laser resurfacing of the face. While expert practices vary, key factors for optimizing outcomes include careful patient selection, counseling, and meticulous pre- and postoperative care. Further research will improve our understanding of this treatment technique

Calibration and performance of the ISO Long-Wavelength Spectrometer

The wavelength and flux calibration, and the in-orbit performance of the Infrared Space Observatory Long-Wavelength Spectrometer (LWS) are described. The LWS calibration is mostly complete and the instrument's performance in orbit is largely as expected before launch. The effects of ionising radiation on the detectors, and the techniques used to minimise them are outlined. The overall sensitivity figures achieved in practice are summarised. The standard processing of LWS data is described

Calibration and performance of the ISO Long-Wavelength Spectrometer

The wavelength and flux calibration, and the in-orbit performance of the Infrared Space Observatory Long-Wavelength Spectrometer (LWS) are described. The LWS calibration is mostly complete and the instrument's performance in orbit is largely as expected before launch. The effects of ionising radiation on the detectors, and the techniques used to minimise them are outlined. The overall sensitivity figures achieved in practice are summarised. The standard processing of LWS data is described