ABSTRACT We present the results of SPT-GMOS, a spectroscopic survey with the Gemini Multi-Object Spectrograph (GMOS) on Gemini South. The targets of SPT-GMOS are galaxy clusters identified in the ...SPT-SZ survey, a millimeter-wave survey of 2500 deg2 of the southern sky using the South Pole Telescope (SPT). Multi-object spectroscopic observations of 62 SPT-selected galaxy clusters were performed between 2011 January and 2015 December, yielding spectra with radial velocity measurements for 2595 sources. We identify 2243 of these sources as galaxies, and 352 as stars. Of the galaxies, we identify 1579 as members of SPT-SZ galaxy clusters. The primary goal of these observations was to obtain spectra of cluster member galaxies to estimate cluster redshifts and velocity dispersions. We describe the full spectroscopic data set and resulting data products, including galaxy redshifts, cluster redshifts, and velocity dispersions, and measurements of several well-known spectral indices for each galaxy: the equivalent width, W, of O ii λλ3727, 3729 and H-δ, and the 4000 break strength, D4000. We use the spectral indices to classify galaxies by spectral type (i.e., passive, post-starburst, star-forming), and we match the spectra against photometric catalogs to characterize spectroscopically observed cluster members as a function of brightness (relative to m ). Finally, we report several new measurements of redshifts for ten bright, strongly lensed background galaxies in the cores of eight galaxy clusters. Combining the SPT-GMOS data set with previous spectroscopic follow-up of SPT-SZ galaxy clusters results in spectroscopic measurements for >100 clusters, or ∼20% of the full SPT-SZ sample.
Transiting planets with orbital periods longer than 40 d are extremely rare among the 5000+ planets discovered so far. The lack of discoveries of this population poses a challenge to research into ...planetary demographics, formation, and evolution. Here, we present the detection and characterization of HD 88986 b, a potentially transiting sub-Neptune, possessing the longest orbital period among known transiting small planets (<4 R ⊕ ) with a precise mass measurement ( σ M /M > 25%). Additionally, we identified the presence of a massive companion in a wider orbit around HD 88986. To validate this discovery, we used a combination of more than 25 yr of extensive radial velocity (RV) measurements (441 SOPHIE data points, 31 ELODIE data points, and 34 HIRES data points), Gaia DR3 data, 21 yr of photometric observations with the automatic photoelectric telescope (APT), two sectors of TESS data, and a 7-day observation of CHEOPS. Our analysis reveals that HD 88986 b, based on two potential single transits on sector 21 and sector 48 which are both consistent with the predicted transit time from the RV model, is potentially transiting. The joint analysis of RV and photometric data show that HD 88986 b has a radius of 2.49 ± 0.18 R ⊕ , a mass of 17.2 −3.8 +4.0 M ⊕ , and it orbits every 146.05 −0.40 +0.43 d around a subgiant HD 88986 which is one of the closest and brightest exoplanet host stars (G2Vtype, R = 1.543 ± 0.065 R ⊙ , V = 6.47 ± 0.01 mag, distance = 33.37 ± 0.04 pc). The nature of the outer, massive companion is still to be confirmed; a joint analysis of RVs, H IPPARCOS , and Gaia astrometric data shows that with a 3 σ confidence interval, its semi-major axis is between 16.7 and 38.8 au and its mass is between 68 and 284 M Jup . HD 88986 b’s wide orbit suggests the planet did not undergo significant mass loss due to extreme-ultraviolet radiation from its host star. Therefore, it probably maintained its primordial composition, allowing us to probe its formation scenario. Furthermore, the cold nature of HD 88986 b (460 ± 8 K), thanks to its long orbital period, will open up exciting opportunities for future studies of cold atmosphere composition characterization. Moreover, the existence of a massive companion alongside HD 88986 b makes this system an interesting case study for understanding planetary formation and evolution.
We report the discovery and characterisation of a giant transiting planet orbiting a nearby M3.5V dwarf (d = 80.4pc, G = 15.1 mag, K=11.2mag, R* = 0.358 ± 0.015 R⊙, M* = 0.340 ± 0.009 M⊙). Using the ...photometric time series from TESS sectors 10, 36, 46, and 63 and near-infrared spectrophotometry from ExTrA, we measured a planetary radius of 0.77 ± 0.03 RJ and an orbital period of 1.52 days. With high-resolution spectroscopy taken by the CFHT/SPIRou and ESO/ESPRESSO spectrographs, we refined the host star parameters (Fe/H = 0.27 ± 0.12) and measured the mass of the planet (0.273 ± 0.006 MJ). Based on these measurements, TOI-4860 b joins the small set of massive planets (>80 ME) found around mid to late M dwarfs (<0.4 R⊙), providing both an interesting challenge to planet formation theory and a favourable target for further atmospheric studies with transmission spectroscopy. We identified an additional signal in the radial velocity data that we attribute to an eccentric planet candidate (e = 0.66 ± 0.09) with an orbital period of 427 ± 7 days and a minimum mass of 1.66 ± 0.26 MJ, but additional data would be needed to confirm this.
We report the discovery and characterisation of a giant transiting planet orbiting a nearby M3.5V dwarf ( d = 80.4pc, G = 15.1 mag, K =11.2mag, R * = 0.358 ± 0.015 R ⊙ , M * = 0.340 ± 0.009 M ⊙ ). ...Using the photometric time series from TESS sectors 10, 36, 46, and 63 and near-infrared spectrophotometry from ExTrA, we measured a planetary radius of 0.77 ± 0.03 R J and an orbital period of 1.52 days. With high-resolution spectroscopy taken by the CFHT/SPIRou and ESO/ESPRESSO spectrographs, we refined the host star parameters (Fe/H = 0.27 ± 0.12) and measured the mass of the planet (0.273 ± 0.006 M J ). Based on these measurements, TOI-4860 b joins the small set of massive planets (>80 M E ) found around mid to late M dwarfs (<0.4 R ⊙ ), providing both an interesting challenge to planet formation theory and a favourable target for further atmospheric studies with transmission spectroscopy. We identified an additional signal in the radial velocity data that we attribute to an eccentric planet candidate ( e = 0.66 ± 0.09) with an orbital period of 427 ± 7 days and a minimum mass of 1.66 ± 0.26 M J , but additional data would be needed to confirm this.
ClusterPyXT is a new software pipeline to generate spectral temperature, X-ray surface brightness, pressure, and density maps from X-ray observations of galaxy clusters. These data products help to ...elucidate the physics of processes occurring within clusters of galaxies, including turbulence, shock fronts, nonthermal phenomena, and the overall dynamics of cluster mergers. ClusterPyXT automates the creation of these data products with minimal user interaction, and allows for rapid analyses of archival data with user defined parameters and the ability to straightforwardly incorporate additional observations. In this paper, we describe in detail the use of this code and release it as an open source Python project on GitHub.
Ghrelin in gastroenteric pathophysiology Locatelli, V; Bresciani, E; Bulgarelli, I ...
Journal of endocrinological investigation,
10/2005, Volume:
28, Issue:
9
Journal Article
Peer reviewed
Ghrelin, an acylated peptide produced predominantly by the stomach, has been discovered to be a natural ligand of the growth hormone secretagogue receptor 1a (GHS-R1a). It is localized in distinct ...cells of the gastric mucosa, mainly distributed in the mid portion of the oxyntic gland characterized by P/D1 granules in man and X/A-like granules in rodents. The ghrelin cell represents the second most frequent endocrine cell type after the enterochromaffin-like cells in gastric oxyntic mucosa, pointing to a potentially relevant role in the physiology of the stomach. Ghrelin has no relevant homology with any known gastrointestinal peptide and displays strong GH-releasing activity both in animals and in humans. However, in addition to stimulating GH secretion, ghrelin possesses several other endocrine and extraendocrine biological activities that are explained by the widespread distribution of ghrelin and GHS-R1a expression. In the rat, ghrelin exerts a control in gastric acid secretion and motility: the gastric acid secretion is stimulated by peripheral administration of high doses of ghrelin, but inhibited by very low doses of ghrelin delivered into the central nervous system. Moreover, ghrelin provides a potent and dose-related gastroprotective action against ethanol- and stress-induced gastric ulcers. The integrity of both nitric oxide (NO) system and capsaicin afferent nerves are required for the gastroprotective effect of ghrelin, whereas the vagus nerve might be involved in conveying ghrelinergic signal from periphery to the brain. In addition, prostaglandins derived by the constitutive cyclooxygenase (COX) activity are essential for the protective activity of ghrelin in ethanol and stress-induced gastric lesions. Given its prevailing role in physiological and pathophysiological gastric function, the discovery of ghrelin will open new perspectives and potential clinical implications in the gastroenteric field.
Abstract
We study the Sunyaev–Zel'dovich effect (SZE) signature in South Pole Telescope (SPT) data for an ensemble of 719 optically identified galaxy clusters selected from 124.6 deg2 of the Dark ...Energy Survey (DES) science verification data, detecting a clear stacked SZE signal down to richness λ ∼ 20. The SZE signature is measured using matched-filtered maps of the 2500 deg2 SPT-SZ survey at the positions of the DES clusters, and the degeneracy between SZE observable and matched-filter size is broken by adopting as priors SZE and optical mass–observable relations that are either calibrated using SPT-selected clusters or through the Arnaud et al. (A10) X-ray analysis. We measure the SPT signal-to-noise ζ–λ relation and two integrated Compton-y
Y
500–λ relations for the DES-selected clusters and compare these to model expectations that account for the SZE–optical centre offset distribution. For clusters with λ > 80, the two SPT-calibrated scaling relations are consistent with the measurements, while for the A10-calibrated relation the measured SZE signal is smaller by a factor of 0.61 ± 0.12 compared to the prediction. For clusters at 20 < λ < 80, the measured SZE signal is smaller by a factor of ∼0.20–0.80 (between 2.3σ and 10σ significance) compared to the prediction, with the SPT-calibrated scaling relations and larger λ clusters showing generally better agreement. We quantify the required corrections to achieve consistency, showing that there is a richness-dependent bias that can be explained by some combination of (1) contamination of the observables and (2) biases in the estimated halo masses. We also discuss particular physical effects associated with these biases, such as contamination of λ from line-of-sight projections or of the SZE observables from point sources, larger offsets in the SZE-optical centring or larger intrinsic scatter in the λ–mass relation at lower richnesses.
The effects of intracerebroventricular (icv) or subcutaneous (sc) hexarelin (Hexa) administration, against gastric ulcers induced by ethanol (50%, 1
ml/rat/os) or Indomethacin (20
mg/kg/os) were ...examined in conscious rats. Hexa at 1
nmol/rat, icv or 10
nmol/kg, sc reduced ethanol-induced ulcers by 47% and 32% respectively. Hexa, but not ghrelin significantly worsened (+40%) Indomethacin-induced ulcers when injected sc. Hexa-gastroprotection against ethanol-induced ulcers was removed by the GHS-R antagonist (
d-Lys
3)-GRPR-6 and by the inhibitor of NO-synthase (NOS)
N
ω-nitro-
l-arginine methyl ester. Semiquantitative RT-PCR assay of gastric NOS mRNA isoforms revealed that the reduction in iNOS-derived NO and the increase of constitutive-derived NO are relevant for the gastroprotection of Hexa against ethanol-induced gastric damage.
We perform a joint analysis of the counts of redMaPPer clusters selected from the Dark Energy Survey (DES) year 1 data and multiwavelength follow-up data collected within the 2500 deg2 South Pole ...Telescope (SPT) Sunyaev-Zel’dovich (SZ) survey. The SPT follow-up data, calibrating the richness-mass relation of the optically selected redMaPPer catalog, enable the cosmological exploitation of the DES cluster abundance data. To explore possible systematics related to the modeling of projection effects, we consider two calibrations of the observational scatter on richness estimates: a simple Gaussian model which account only for the background contamination (BKG), and a model which further includes contamination and incompleteness due to projection effects (PRJ). Assuming either a ΛCDM+Σmν or wCDM+Σmν cosmology, and for both scatter models, we derive cosmological constraints consistent with multiple cosmological probes of the low and high redshift Universe, and in particular with the SPT cluster abundance data. Furthermore, this result demonstrates that the DES Y1 and SPT cluster counts provide consistent cosmological constraints, if the same mass calibration data set is adopted. It thus supports the conclusion of the DES Y1 cluster cosmology analysis which interprets the tension observed with other cosmological probes in terms of systematics affecting the stacked weak lensing analysis of optically selected low–richness clusters. Finally, we analyze the first combined optically SZ selected cluster catalog obtained by including the SPT sample above the maximum redshift probed by the DES Y1 redMaPPer sample (z=0.65). Besides providing a mild improvement of the cosmological constraints, this data combination serves as a stricter test of our scatter models: the PRJ model, providing scaling relations consistent between the two abundance and multiwavelength follow-up data, is favored over the BKG model.
We present a quantitative study of the X-ray morphology of galaxy clusters, as a function of their detection method and redshift. We analyze two separate samples of galaxy clusters: a sample of 36 ...clusters at 0.35<z<0.9 selected in the X-ray with the ROSAT PSPC 400 deg{sup 2} survey, and a sample of 90 clusters at 0.25<z<1.2 selected via the Sunyaev–Zel’dovich (SZ) effect with the South Pole Telescope. Clusters from both samples have similar-quality Chandra observations, which allow us to quantify their X-ray morphologies via two distinct methods: centroid shifts (w) and photon asymmetry (A{sub phot}). The latter technique provides nearly unbiased morphology estimates for clusters spanning a broad range of redshift and data quality. We further compare the X-ray morphologies of X-ray- and SZ-selected clusters with those of simulated clusters. We do not find a statistically significant difference in the measured X-ray morphology of X-ray and SZ-selected clusters over the redshift range probed by these samples, suggesting that the two are probing similar populations of clusters. We find that the X-ray morphologies of simulated clusters are statistically indistinguishable from those of X-ray- or SZ-selected clusters, implying that the most important physics for dictating the large-scale gas morphology (outside of the core) is well-approximated in these simulations. Finally, we find no statistically significant redshift evolution in the X-ray morphology (both for observed and simulated clusters), over the range of z∼0.3 to z∼1, seemingly in contradiction with the redshift-dependent halo merger rate predicted by simulations.
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