A boxy bulge in the Milky Way. Inversion of the stellar statistics equation with 2MASS data

Inverting the stellar statistics equation from 2MASS star counts, we obtain the 3D density distribution of the Galactic bulge as well as its luminosity function in the K-band. This results in a boxy bulge with axial ratios 1:0.5:0.4 and a major axis angle with respect to the Sun-galactic center of $20^\circ-35^\circ$.Comment: 5 pages, accepted to be published in A&

Galaxies behind the Galactic plane: First results and perspectives from the VVV Survey

Vista Variables in The Via Lactea (VVV) is an ESO variability survey that is performing observations in near infrared bands (ZYJHKs) towards the Galactic bulge and part of the disk with the completeness limits at least 3 mag deeper than 2MASS. In the present work, we searched in the VVV survey data for background galaxies near the Galactic plane using ZYJHKs photometry that covers 1.636 square degrees. We identified 204 new galaxy candidates by analyzing colors, sizes, and visual inspection of multi-band (ZYJHKs) images. The galaxy candidates colors were also compared with the predicted ones by star counts models considering a more realistic extinction model at the same completeness limits observed by VVV. A comparison of the galaxy candidates with the expected one by Milennium simulations is also presented. Our results increase the number density of known galaxies behind the Milky Way by more than one order of magnitude. A catalog with galaxy properties including ellipticity, Petrosian radii and ZYJHKs magnitudes is provided, as well as comparisons of the results with other surveys of galaxies towards Galactic plane.Comment: 27 pages, 10 figures, 2 tables; in press at The Astronomical Journa

COBE's Galactic Bar and Disk

A model of the bar and old stellar disk of the Galaxy has been derived from the survey of the Diffuse Infrared Background Experiment (DIRBE) of the Cosmic Background Explorer at wavelengths of 1.25, 2.2, 3.5, and 4.9 microns. It agrees very well with the data, except in directions in which the near- infrared optical depth is high. Among the conclusions drawn from the model: The Sun is located approximately 16.5 pc above the midpoint of the Galactic plane. The disk has an outer edge four kpc from the Sun, and is warped like the HI layer. It has a central hole roughly the diameter of the inner edge of the "three-kiloparsec" molecular cloud ring, and within that hole lies a bright, strong, "early-type" bar, tilted approximately 14 degrees from the Sun-Galactic center line. The model has 47 free parameters. The model is discussed in detail and contour plots and images of the residuals presented.Comment: 30 pages, LaTeX, with 15 figures, 3 JPG and 12 GIF. Accepted by ApJ. Corrected a factor-of-2 error in total luminosity and replaced 2 corrupted JPEG files. Relevant images of the Galactic J-K and K-L colors can be found at http://www.gsfc.nasa.gov/astro/cobe/dirbe_image.htm

The COBE Diffuse Infrared Background Experiment Search for the Cosmic Infrared Background: I. Limits and Detections

The DIRBE on the COBE spacecraft was designed primarily to conduct systematic search for an isotropic CIB in ten photometric bands from 1.25 to 240 microns. The results of that search are presented here. Conservative limits on the CIB are obtained from the minimum observed brightness in all-sky maps at each wavelength, with the faintest limits in the DIRBE spectral range being at 3.5 microns (\nu I_\nu < 64 nW/m^2/sr, 95% CL) and at 240 microns (\nu I_\nu < 28 nW/m^2/sr, 95% CL). The bright foregrounds from interplanetary dust scattering and emission, stars, and interstellar dust emission are the principal impediments to the DIRBE measurements of the CIB. These foregrounds have been modeled and removed from the sky maps. Assessment of the random and systematic uncertainties in the residuals and tests for isotropy show that only the 140 and 240 microns data provide candidate detections of the CIB. The residuals and their uncertainties provide CIB upper limits more restrictive than the dark sky limits at wavelengths from 1.25 to 100 microns. No plausible solar system or Galactic source of the observed 140 and 240 microns residuals can be identified, leading to the conclusion that the CIB has been detected at levels of \nu I_\nu = 25+-7 and 14+-3 nW/m^2/sr at 140 and 240 microns respectively. The integrated energy from 140 to 240 microns, 10.3 nW/m^2/sr, is about twice the integrated optical light from the galaxies in the Hubble Deep Field, suggesting that star formation might have been heavily enshrouded by dust at high redshift. The detections and upper limits reported here provide new constraints on models of the history of energy-releasing processes and dust production since the decoupling of the cosmic microwave background from matter.Comment: 26 pages and 5 figures, accepted for publication in the Astrophyical Journa

Open cluster survival within the solar circle: Teutsch145 and Teutsch146

Teutsch145 and Teutsch146 are shown to be open clusters (OCs) orbiting well inside the Solar circle, a region where several dynamical processes combine to disrupt most OCs on a time-scale of a few 10^8yrs. BVI photometry from the GALILEO telescope is used to investigate the nature and derive the fundamental and structural parameters of the optically faint and poorly-known OCs Teutsch145 and 146. These parameters are computed by means of field-star decontaminated colour-magnitude diagrams (CMDs) and stellar radial density profiles (RDPs). Cluster mass estimates are made based on the intrinsic mass functions (MFs). We derive the ages 200+100-50Myr and 400+/-100Myr, and the distances from the Sun 2.7+/-0.3kpc and 3.8+/-0.2kpc, respectively for Teutsch145 and 146. Their integrated apparent and absolute magnitudes are m_V ~ 12.4, m_V ~ 13.3, M_V ~- 5.6 and M_V ~- 5.3. The MFs (detected for stars with m>1Msun) have slopes similar to Salpeter's IMF. Extrapolated to the H-burning limit, the MFs would produce total stellar masses of ~1400Msun, typical of relatively massive OCs. Both OCs are located deep into the inner Galaxy and close to the Crux-Scutum arm. Since cluster-disruption processes are important, their primordial masses must have been higher than the present-day values. The conspicuous stellar density excess observed in the innermost bin of both RDPs might reflect the dynamical effects induced by a few 10^8yrs of external tidal stress.Comment: 8 pagas with 9 figs. Accepted by MNRA

Characterisation of 15 overlooked Ruprecht clusters with ages within 400Myr and 3Gyr

We derive fundamental, structural, and photometric parameters of 15 overlooked Ruprecht (hereafter Ru) star clusters by means of 2MASS photometry and field-star decontamination. Ru\,1, 10, 23, 26, 27, 34, 35, 37, 41, 54, 60, 63, 66, and 152 are located in the third Galactic quadrant, while Ru\,174 is in the first. With the constraints imposed by the field-decontaminated colour-magnitude diagrams (CMDs) and stellar radial density profiles (RDPs), we derive ages in the range 400\,Myr --- 1\,Gyr, except for the older Ru\,37, with $\sim3$\,Gyr. Distances from the Sun are within \rm1.5\la\ds(kpc)\la8.0. The RDPs are well-defined and can be described by a King-like profile for most of the radial range, except for Ru\,23, 27, 41, 63, and 174, which present a conspicuous stellar density excess in the central region. The clusters dwell between (or close to) the Perseus and Sagittarius-Carina arms. We derive evidence in favour of cluster size increasing with distance to the Galactic plane (\zgc), which is consistent with a low frequency of tidal stress associated with high-|\zgc| regions. The clusters are rather faint even in the near-infrared, with apparent integrated \jj\ magnitudes within 6.4\la m_J\la9.8, while their absolute magnitudes are -6.6\la M_J\la-2.6. Extrapolation of the relation between $M_V$ and $M_J$, derived for globular clusters, suggests that they are low-luminosity optical clusters, with -5\la M_V\la-1.Comment: The paper contains 11 figures and 3 tables. Accepted by MNRAS

Observations of Low-Latitude Plasma Density Enhancements and their Associated Plasma Drifts

Plasma density structures are frequently encountered in the nighttime low-latitude ionosphere by probes on the Communication/Navigation Outage Forecasting System (C/NOFS) satellite. Of particular interest to us here are plasma density enhancements, which are typically observed +/- 15 deg away from the magnetic equator. The low inclination of the C/NOFS satellite offers an unprecedented opportunity to examine these structures and their associated electric fields and plasma velocities, including their field-aligned components, along an east-west trajectory. Among other observations, the data reveal a clear asymmetry in the velocity structure within and around these density enhancements. Previous observations have shown that the peak change in drift velocity associated with a density enhancement occurs simultaneously both perpendicular and parallel to the magnetic field, while the 1results in this paper show that the peak change in parallel fl ow typically occurs 25-100 km to the east of the peak perpendicular ow. We discuss this and other aspects of the observations in relation to the characteristics of the plasma depletions formed near the magnetic equator detected by the same probes on the C/NOFS satellite and to previous observations and theories

Efficacy and Tolerability of Adjunctive Intravenous Sodium Nitroprusside Treatment for Outpatients With Schizophrenia: A Randomized Clinical Trial

Importance: Antipsychotic medications for the treatment of schizophrenia have limitations, and new treatments are needed. A prior pilot investigation suggested that adjunctive sodium nitroprusside (SNP) administered intravenously had rapid efficacy in the treatment of patients with schizophrenia. Objective: To determine the efficacy and tolerability of intravenous SNP infused at a rate of 0.5 mug/kg/min for 4 hours in patients with schizophrenia with some degree of treatment resistance. Design, Setting, and Participants: Multicenter, randomized, double-blind acute treatment study using a sequential parallel comparison design conducted in two 2-week phases at 4 academic medical centers beginning May 20, 2015, and ending March 31, 2017. Participants were adults 18 to 65 years of age with a diagnosis of schizophrenia as confirmed by the Structured Clinical Interview for DSM-IV, taking antipsychotic medication for at least 8 weeks, and had at least 1 failed trial of an antipsychotic medication within the past year. A total of 90 participants consented, 60 participants enrolled, and 52 participants were included in the analyses. A modified intent-to-treat analysis was used. Interventions: Participants were randomized in a 1:1:1 ratio to 1 of 3 treatment sequences: SNP and SNP, placebo and SNP, and placebo and placebo. The SNP and SNP group received SNP in phase 1 and SNP in phase 2 for the purpose of blinding, but the data from phase 2 were not included in the results. The placebo and SNP group received placebo in phase 1 and SNP in phase 2. If there was no response to placebo in phase 1, data from phase 2 were included in the analyses. The placebo and placebo group received placebo in both phases; if there was no response to placebo in phase 1, data from phase 2 were included in the analyses. Main Outcomes and Measures: Effectiveness of SNP compared with placebo in improving Positive and Negative Syndrome Scale (PANSS) total, positive, and negative scores across each 2-week phase. Results: Fifty-two participants (12 women and 40 men) were included in the study. In the SNP and SNP group, the mean (SD) age was 47.1 (10.5) years. In the placebo and SNP group, the mean (SD) age was 45.9 (12.3) years. In the placebo and placebo group, the mean (SD) age was 40.4 (11.0) years. There were no significant differences between the SNP and placebo groups at baseline or in change from baseline for PANSS-total (weighted beta = -1.04; z = -0.59; P = .57), PANSS-positive (weighted beta = -0.62; z = -0.93; P = .35), or PANSS-negative (weighted beta = -0.12; z = -0.19; P = .85) scores. No significant differences in safety or tolerability measures were identified. Conclusions and Relevance: Although intravenous SNP is well tolerated, it was not an efficacious adjunctive treatment of positive or negative symptoms of psychosis among outpatients with schizophrenia with prior history of treatment resistance. Trial Registration: ClinicalTrials.gov identifier: NCT02164981

The old Galactic open clusters FSR1716 and Czernik23

Open clusters older than $\sim4$ Gyr are rare in the Galaxy. Affected by a series of mass-decreasing processes, the stellar content of most open clusters dissolves into the field in a time-scale shorter than $\sim1$ Gyr. In this sense, improving the statistics of old objects may provide constraints for a better understanding of the dynamical dissolution of open clusters. Isochrone fits indicate that FSR 1716 is more probably an old ($\sim7$ Gyr) and absorbed (\aV=6.3\pm0.2) open cluster, located $\approx0.6$ kpc inside the Solar circle in a contaminated central field. However, we cannot rule out the possibility of a low-mass, loose globular cluster. Czernik 23 is shown to be an almost absorption-free open cluster, $\sim5$ Gyr old, located about 2.5 kpc towards the anti-centre. In both cases, Solar and sub-Solar ($[Fe/H]\sim-0.5$) metallicity isochrones represent equally well the stellar sequences. Both star clusters have a low mass content (\la200 \ms) presently stored in stars. Their relatively small core and cluster radii are comparable to those of other open clusters of similar age. These structural parameters are probably consequence of the several Gyrs of mass loss due to stellar evolution, tidal interactions with the disk (and bulge in the case of FSR 1716), and possibly giant molecular clouds. Czernik 23, and especially FSR 1716, are rare examples of extreme dynamical survivors. The identification of both as such represents an increase of $\approx10$ to the known population of open clusters older than $\sim4$ Gyr in the Galaxy.Comment: 15 pages and 13 figures. Accepted by A&