Pan-STARRS Photometric and Astrometric Calibration Magnier, Eugene. A.; Schlafly, Edward. F.; Finkbeiner, Douglas P. ...
The Astrophysical journal. Supplement series,
11/2020, Letnik:
251, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Abstract
We present the details of the photometric and astrometric calibration of the Pan-STARRS1 3
π
Survey. The photometric goals were to reduce the systematic effects introduced by the camera and ...detectors, and to place all of the observations onto a photometric system with consistent zero-points over the entire area surveyed, the ≈30,000 deg
2
north of
δ
= −30°. Using external comparisons, we demonstrate that the resulting photometric system is consistent across the sky to between 7 and 12.4 mmag depending on the filter. For bright stars, the systematic error floor for individual measurements is (
σ
g
,
σ
r
,
σ
i
,
σ
z
,
σ
y
) = (14, 14, 15, 15, 18) mmag. The astrometric calibration compensates for similar systematic effects so that positions, proper motions, and parallaxes are reliable as well. The bright-star systematic error floor for individual astrometric measurements is 16 mas. The Pan-STARRS Data Release 2 (DR2) astrometric system is tied to the Gaia DR1 coordinate frame with a systematic uncertainty of ∼5 mas.
Abstract
The Pan-STARRS1 (PS1) Science Consortium has carried out a set of imaging surveys using the 1.4 gigapixel GPC1 camera on the PS1 telescope. As this camera is composed of many individual ...electronic readouts and covers a very large field of view, great care was taken to ensure that the many instrumental effects were corrected to produce the most uniform detector response possible. We present the image-detrending steps used as part of the processing of the data contained within the public release of Pan-STARRS1 Data Release 1 (DR1). In addition to the single image processing, the methods used to transform the 375,573 individual exposures into a common sky-oriented grid are discussed, as well as those used to produce both the image stack and difference combination products.
Abstract
Over 3 billion astronomical sources have been detected in the more than 22 million orthogonal transfer CCD images obtained as part of the Pan-STARRS1 3
π
survey. Over 85 billion instances of ...those sources have been automatically detected and characterized by the Pan-STARRS Image Processing Pipeline photometry software,
psphot
. This fast, automatic, and reliable software was developed for the Pan-STARRS project but is easily adaptable to images from other telescopes. We describe the analysis of the astronomical sources by
psphot
in general as well as for the specific case of the third processing version used for the first two public releases of the Pan-STARRS 3
π
Survey data.
As of 2012 January 21, the Pan-STARRS 1 3pi Survey has observed the 3/4 of the sky visible from Hawaii with a minimum of 2 and mean of 7.6 observations in five filters, g sub(P1), r sub(P1), i ...sub(P1), z sub(P1), y sub(P1). Now at the end of the second year of the mission, we are in a position to make an initial public release of a portion of this unprecedented data set. This article describes the PS1 Photometric Ladder, Release 12.01. This is the first of a series of data releases to be generated as the survey coverage increases and the data analysis improves. The Photometric Ladder has rungs every hour in right ascension and at four intervals in declination. We will release updates with increased area coverage (more rungs) from the latest data set until the PS1 survey and the final re-reduction are completed. The currently released catalog presents photometry of ~ 1000 objects per square degree in the rungs of the ladder. Saturation occurs at g sub(P1), r sub(P1), i sub(P1) ~ 13.5; z sub(P1) ~ 13.0; and y sub(P1) ~ 12.0. Photometry is provided for stars down to g sub(P1), r sub(P1), z sub(P1) ~ 19.1 in the AB system. This data release depends on the rigid "Ubercal" photometric calibration using only the photometric nights, with systematic uncertainties of (8.0, 7.0, 9.0, 10.7, 12.4) mmag in (g sub(P1), r sub(P1), i sub(p1), z sub(P1), y sub(P1)). Areas covered only with lower quality nights are also included, and have been tied to the Ubercal solution via relative photometry; photometric accuracy of the non-photometric regions is lower and should be used with caution.
Although the effects of postherpetic neuralgia on physical and emotional functioning have been examined in a number of studies, the impact of acute pain in herpes zoster ("shingles") on ...health-related quality of life has been neglected. We describe the characteristics of herpes zoster pain and examine its relationship to physical, role, social, and emotional functioning in 110 patients with herpes zoster. When we controlled for relevant covariates, we found that greater pain burden, as assessed by the product of pain intensity and duration, was associated with poorer physical functioning, increased emotional distress, and decreased role and social functioning. The results demonstrate that herpes zoster pain has broad effects on the daily lives of patients and on their emotional health. The increasing incidence of herpes zoster that can be anticipated as the population ages requires that clinical trials that examine interventions to prevent or treat herpes zoster pain be given a high priority.
Abstract
We present the discovery of a 360 au separation T3 companion to the tight (3.1 au) M4.5+M6.5 binary 2MASS J02132062+3648506. This companion was identified using Pan-STARRS 1 data and despite ...its relative proximity to the Sun (22.2$_{-4.0}^{+6.4}$ pc; Pan-STARRS 1 parallax) and brightness (J = 15.3), it appears to have been missed by previous studies due to its position near a diffraction spike in 2MASS. The close M dwarf binary has active X-ray and Hα emission and shows evidence for UV flares. The binary's weak GALEX UV emission and strong Na i 8200 Å Na absorption lead us to an age range of ∼1–10 Gyr. Applying this age range to evolutionary models implies that the wide companion has a mass of 0.063 ± 0.009 M⊙. 2MASS J0213+3648 C provides a relatively old benchmark close to the L/T transition and acts as a key, older comparison to the much younger early-T companions HN Peg B and GU Psc b.
Recent searches by unbiased, wide-field surveys have uncovered a group of extremely luminous optical transients. The initial discoveries of SN 2005ap by the Texas Supernova Search and SCP-06F6 in a ...deep Hubble pencil beam survey were followed by the Palomar Transient Factory confirmation of host redshifts for other similar transients. The transients share the common properties of high optical luminosities (peak magnitudes ~--21 to --23), blue colors, and a lack of H or He spectral features. The physical mechanism that produces the luminosity is uncertain, with suggestions ranging from jet-driven explosion to pulsational pair instability. Here, we report the most detailed photometric and spectral coverage of an ultra-bright transient (SN 2010gx) detected in the Pan-STARRS 1 sky survey. In common with other transients in this family, early-time spectra show a blue continuum and prominent broad absorption lines of O II. However, about 25 days after discovery, the spectra developed type Ic supernova features, showing the characteristic broad Fe II and Si II absorption lines. Detailed, post-maximum follow-up may show that all SN 2005ap and SCP-06F6 type transients are linked to supernovae Ic. This poses problems in understanding the physics of the explosions: there is no indication from late-time photometry that the luminosity is powered by 56Ni, the broad light curves suggest very large ejected masses, and the slow spectral evolution is quite different from typical Ic timescales. The nature of the progenitor stars and the origin of the luminosity are intriguing and open questions.
Background: Delirium is an acute organ dysfunction common amongst patients treated in intensive care units. The associated morbidity and mortality are known to be substantial. Previous surveys have ...described which screening tools are used to diagnose delirium and which medications are used to treat delirium, but these data are not available for the United Kingdom. Aim: This survey aimed to describe the UK management of delirium by consultant intensivists. Additionally, knowledge and attitudes towards management of delirium were sought. The results will inform future research in this area. Methods: A national postal survey of members of the UK Intensive Care Society was performed. A concise two page questionnaire survey was sent, with a second round of surveys sent to non-respondents after 6 weeks. The questionnaire was in tick-box format. Results: Six hundred and eighty-one replies were received from 1308 questionnaires sent, giving a response rate of 52%. Twenty-five percent of respondents routinely screen for delirium, but of these only 55% use a screening tool validated for use in intensive care. The majority (80%) of those using a validated instrument used the Confusion Assessment Method for the Intensive Care Unit. Hyperactive delirium is treated pharmacologically by 95%; hypoactive delirium is treated pharmacologically by 25%, with haloperidol the most common agent used in both. Over 80% of respondents agreed that delirium prolongs mechanical ventilation and hospital stay and requires active treatment. Conclusions: This UK survey demonstrates screening for delirium is sporadic. Pharmacological treatment is usually with haloperidol in spite of the limited evidence to support this practice. Hypoactive delirium is infrequently treated pharmacologically.
Primary mitochondrial dysfunction commonly leads to failure in cellular adaptation to stress. Paradoxically, however, nonsynonymous mutations of mitochondrial DNA (mtDNA) are frequently found in ...cancer cells and may have a causal role in the development of resistance to genotoxic stress induced by common chemotherapeutic agents, such as cis-diammine-dichloroplatinum(II) (cisplatin, CDDP). Little is known about how these mutations arise and the associated mechanisms leading to chemoresistance. Here, we show that the development of adaptive chemoresistance in the A549 non-small-cell lung cancer cell line to CDDP is associated with the hetero- to homoplasmic shift of a nonsynonymous mutation in MT-ND2, encoding the mitochondrial Complex-I subunit ND2. The mutation resulted in a 50% reduction of the NADH:ubiquinone oxidoreductase activity of the complex, which was compensated by increased biogenesis of respiratory chain complexes. The compensatory mitochondrial biogenesis was most likely mediated by the nuclear co-activators peroxisome proliferator-activated receptor gamma co-activator-1α (PGC-1α) and PGC-1β, both of which were significantly upregulated in the CDDP-resistant cells. Importantly, both transient and stable silencing of PGC-1β re-established the sensitivity of these cells to CDDP-induced apoptosis. Remarkably, the PGC-1β-mediated CDDP resistance was independent of the mitochondrial effects of the co-activator. Altogether, our results suggest that partial respiratory chain defects because of mtDNA mutations can lead to compensatory upregulation of nuclear transcriptional co-regulators, in turn mediating resistance to genotoxic stress.
Summary
Background
We hypothesised that grade/appearance for upper respiratory tract (URT) disorders identified at the first overground endoscopy (OGE) examination would vary at subsequent ...examinations.
Objectives
To compare OGE examinations from horses evaluated on at least two occasions under similar exercise conditions without treatment intervention.
Study design
Retrospective cohort.
Methods
Pre‐exercise and exercising OGE recordings from Thoroughbred horses undergoing multiple examinations under similar exercise conditions were reviewed, with the first two recordings for each horse statistically evaluated. Paired Wilcoxon signed‐rank tests were used to assess differences in exercise and physiological parameters between examinations. Z‐tests were used to assess the proportion of changes in URT disorder grade/appearance between examinations. A McNemar's test was used to compare the proportion of horses with each disorder at each examination. Test–retest reliability across examinations was assessed using Spearman's ρ, and ordered logistic regression used to explore temporal effects on repeatability. Lattice plots were constructed to view variability in disorders over time.
Results
Seventy‐eight horses (median age 2.4 years) with 195 resting endoscopic examinations including 72/78 horses with 179 pre‐exercise and exercising OGE examinations were evaluated. Median time between examinations was 226.5 days with no differences between exercise and physiological parameters. Grades significantly varied between examinations for all disorders, and in particular for palatal instability (PI) and epiglottic grade at rest. A temporal link between examination interval and disorder grade change was identified for PI and resting arytenoid asymmetry.
Main limitations
OGE re‐examinations within a shorter, more consistent time‐frame would allow determination of intrahorse variability. The sample size was inadequate to conclusively establish temporal links between disorders and time between examinations.
Conclusions
Variability for most URT abnormalities identified with OGE should be considered when making therapeutic decisions based on a single examination and may partially explain development of additional URT conditions after surgical intervention.
The Summary is available in Portuguese ‐ see Supporting Information
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