119 research outputs found
Near-infrared photometry of WISE J085510.74-071442.5
IndexaciĂłn: Web of ScienceAims. We aim at obtaining near-infrared photometry and deriving the mass, age, temperature, and surface gravity of WISE J085510.74 071442.5 (J0855 0714), which is the coolest object beyond the solar system currently known.
Methods. We used publicly available data from the archives of the Hubble Space Telescope (HST) and the Very Large Telescope (VLT) to determine the emission of this source at 1.153 mu m (F110W) and 1.575 mu m (CH4-o ff). J0855 0714 was detected at both wavelengths with a signal-to-noise ratio of approximate to 10 (F110W) and approximate to 4 (CH4-off) at the peak of the corresponding point-spread-functions.
Results. This is the first detection of J0855 0714 in the H-band wavelengths. We measured 26.31 +/- 0.10 and 23.22 +/- 0.35 mag in F110W and CH4-o ff (Vega system). J0855 0714 remains unresolved in the HST images that have a spatial resolution of 0.22 0 0. Companions at separations of 0.5 AU (similar mass and brightness) and at similar to 1 AU approximate to 1 mag fainter in the F110W filter) are discarded. By combining the new data with published photometry, including non-detections, we build the spectral energy distribution of J0855 0714 from 0.89 through 22.09 mu m, and contrast it against current solar-metallicity models of planetary atmospheres. We determine that the best spectral fit yields a temperature of 225 250 K, a bolometric luminosity of log L/L-circle dot = 8 : 57, and a high surface gravity of log g = 5 : 0 (cm s(2)), which suggests an old age although a gravity this high is not fully compatible with evolutionary models. After comparing our data with the cooling theory for brown dwarfs and planets, we infer a mass in the interval 2 10 MJup for ages of 1 12 Gyr and high atmospheric gravities of log g greater than or similar to 3.5 (cm s(2)). If it had the age of the Sun, J0855 0714 would be a approximate to 5-M-Jup free-floating planetary-mass object.
Conclusions. J0855 0714 meets the mass values previously determined for free-floating planetary-mass objects discovered in starforming regions and young stellar clusters. Based on extrapolations of the substellar mass functions of young clusters to the field, as many J0855 0714-like objects as M5-L2 stars may be expected to populate the solar neighborhood.http://www.aanda.org/articles/aa/pdf/2016/08/aa28662-16.pd
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
Mutations in ASXL1 are associated with poor prognosis across the spectrum of malignant myeloid diseases
The ASXL1 gene is one of the most frequently mutated genes in malignant myeloid diseases. The ASXL1 protein belongs to protein complexes involved in the epigenetic regulation of gene expression. ASXL1 mutations are found in myeloproliferative neoplasms (MPN), myelodysplastic syndromes (MDS), chronic myelomonocytic leukemia (CMML) and acute myeloid leukemia (AML). They are generally associated with signs of aggressiveness and poor clinical outcome. Because of this, a systematic determination of ASXL1 mutational status in myeloid malignancies should help in prognosis assessment
The CARMENES Search for Exoplanets around M Dwarfs: A Low-mass Planet in the Temperate Zone of the Nearby K2-18
. I.R. and J.C.M. acknowledge support
by the Spanish Ministry of Economy and Competitiveness
(MINECO) and the Fondo Europeo de Desarrollo Regional
(FEDER) through grant ESP2016-80435-C2-1-R, as well as
the support of the Generalitat de Catalunya/CERCA program.
A.P.H. acknowledges the support of the Deutsche Forschungsgemeinschaft
(DFG) grant HA 3279/11-1. J.A.C.,
P.J.A. and D.M. acknowledge support by the Spanish
Ministry of Economy and Competitiveness (MINECO) from
projects AYA2016-79425-C3-1, 2, 3-P. V.J.S.B. is supported
by program AYA2015-69350-C3-2-P from Spanish Ministry
of Economy and Competitiveness (MINECO
ASXL2 is essential for haematopoiesis and acts as a haploinsufficient tumour suppressor in leukemia
Additional sex combs-like (ASXL) proteins are mammalian homologues of additional sex combs (Asx), a regulator of trithorax and polycomb function in Drosophila. While there has been great interest in ASXL1 due to its frequent mutation in leukemia, little is known about its paralog ASXL2, which is frequently mutated in acute myeloid leukemia patients bearing the RUNX1-RUNX1T1 (AML1-ETO) fusion. Here we report that ASXL2 is required for normal haematopoiesis with distinct, non-overlapping effects from ASXL1 and acts as a haploinsufficient tumour suppressor. While Asxl2 was required for normal haematopoietic stem cell self-renewal, Asxl2 loss promoted AML1-ETO leukemogenesis. Moreover, ASXL2 target genes strongly overlapped with those of RUNX1 and AML1-ETO and ASXL2 loss was associated with increased chromatin accessibility at putative enhancers of key leukemogenic loci. These data reveal that Asxl2 is a critical regulator of haematopoiesis and mediates transcriptional effects that promote leukemogenesis driven by AML1-ETO
The CARMENES search for exoplanets around M dwarfs High-resolution optical and near-infrared spectroscopy of 324 survey stars
The CARMENES radial velocity (RV) survey is observing 324 M dwarfs to search for any orbiting planets. In this paper, we present the survey sample by publishing one CARMENES spectrum for each M dwarf. These spectra cover the wavelength range 520â1710 nm at a resolution of at least R >80 000, and we measure its RV, HÎą emission, and projected rotation velocity. We present an atlas of high-resolution M-dwarf spectra and compare the spectra to atmospheric models. To quantify the RV precision that can be achieved in low-mass stars over the CARMENES wavelength range, we analyze our empirical information on the RV precision from more than 6500 observations. We compare our high-resolution M-dwarf spectra to atmospheric models where we determine the spectroscopic RV information content, Q, and signal-to-noise ratio. We find that for all M-type dwarfs, the highest RV precision can be reached in the wavelength range 700â900 nm. Observations at longer wavelengths are equally precise only at the very latest spectral types (M8 and M9). We demonstrate that in this spectroscopic range, the large amount of absorption features compensates for the intrinsic faintness of an M7 star. To reach an RV precision of 1 m sâ1 in very low mass M dwarfs at longer wavelengths likely requires the use of a 10 m class telescope. For spectral types M6 and earlier, the combination of a red visual and a near-infrared spectrograph is ideal to search for low-mass planets and to distinguish between planets and stellar variability. At a 4 m class telescope, an instrument like CARMENES has the potential to push the RV precision well below the typical jitter level of 3â4 m sâ1
Ischaemic conditioning and targeting reperfusion injury: a 30 year voyage of discovery
To commemorate the auspicious occasion of the 30th anniversary of IPC, leading pioneers in the field of cardioprotection gathered in Barcelona in May 2016 to review and discuss the history of IPC, its evolution to IPost and RIC, myocardial reperfusion injury as a therapeutic target, and future targets and strategies for cardioprotection. This article provides an overview of the major topics discussed at this special meeting and underscores the huge importance and impact, the discovery of IPC has made in the field of cardiovascular research
Gliese 49: activity evolution and detection of a super-Earth A HADES and CARMENES collaboration
Small planets around low-mass stars often show orbital periods in a range
that corresponds to the temperate zones of their host stars which are therefore
of prime interest for planet searches. Surface phenomena such as spots and
faculae create periodic signals in radial velocities and in observational
activity tracers in the same range, so they can mimic or hide true planetary
signals. We aim to detect Doppler signals corresponding to planetary
companions, determine their most probable orbital configurations, and
understand the stellar activity and its impact on different datasets. We
analyze 22 years of data of the M1.5V-type star Gl49 (BD+61 195) including
HARPS-N and CARMENES spectrographs, complemented by APT2 and SNO photometry.
Activity indices are calculated from the observed spectra, and all datasets are
analyzed with periodograms and noise models. We investigate how the variation
of stellar activity imprints on our datasets. We further test the origin of the
signals and investigate phase shifts between the different sets. To search for
the best-fit model we maximize the likelihood function in a Markov Chain Monte
Carlo approach. As a result of this study, we are able to detect the
super-Earth Gl49b with a minimum mass of 5.6 Ms. It orbits its host star with a
period of 13.85d at a semi-major axis of 0.090 au and we calculate an
equilibrium temperature of 350 K and a transit probability of 2.0%. The
contribution from the spot-dominated host star to the different datasets is
complex, and includes signals from the stellar rotation at 18.86d, evolutionary
time-scales of activity phenomena at 40-80d, and a long-term variation of at
least four years
Aligning the CMS Muon Chambers with the Muon Alignment System during an Extended Cosmic Ray Run
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