Stellar Kinematics of the Double Nucleus of M31

We report observations of the double nucleus of M31 with the f/48 long-slit spectrograph of the HST Faint Object Camera. We obtain a total exposure of 19,000 sec. over 7 orbits, with the 0.063-arcsec-wide slit along the line between the two brightness peaks (PA 42). A spectrum of Jupiter is used as a spectral template. The rotation curve is resolved, and reaches a maximum amplitude of ~250 km/s roughly 0.3 arcsec either side of a rotation center lying between P1 and P2, 0.16 +/- 0.05 arcsec from the optically fainter P2. We find the velocity dispersion to be < 250 km/s everywhere except for a narrow ``dispersion spike'', centered 0.06 +/- 0.03 arcsec on the anti-P1 side of P2, in which sigma peaks at 440 +/- 70 km/s. At much lower confidence, we see local disturbances to the rotation curve at P1 and P2, and an elevation in sigma at P1. At very low significance we detect a weak asymmetry in the line-of-sight velocity distribution opposite to the sense usually encountered. Convolving our V and sigma profiles to CFHT resolution, we find good agreement with the results of Kormendy & Bender (1998, preprint), though there is a 20% discrepancy in the dispersion that cannot be attributed to the dispersion spike. Our results are not consistent with the location of the maximum dispersion as found by Bacon et al. We find that the sinking star cluster model of Emsellem & Combes (1997) does not reproduce either the rotation curve or the dispersion profile. The eccentric disk model of Tremaine (1995) fares better, and can be improved somewhat by adjusting the original parameters. However, detailed modeling will require dynamical models of significantly greater realism.Comment: 29 pages, Latex, AASTeX v4.0, with 7 eps figures. To appear in The Astronomical Journal, February 199

Measurements of Far-UV Emission from Elliptical Galaxies at z=0.375

The ``UV upturn'' is a sharp rise in spectra of elliptical galaxies shortward of rest-frame 2500 A. It is a ubiquitous phenomenon in nearby giant elliptical galaxies, and is thought to arise primarily from low-mass evolved stars on the extreme horizontal branch and beyond. Models suggest that the UV upturn is a very strong function of age for these old stellar populations, increasing as the galaxy gets older. In some models the change in UV/optical flux ratio is a factor of 25 over timescales of less than 3 Gyr. To test the predictions for rapid evolution of the UV upturn, we have observed a sample of normal elliptical galaxies in the z=0.375 cluster Abell 370 with the Faint Object Camera aboard the Hubble Space Telescope. A combination of two long-pass filters was used to isolate wavelengths shortward of rest-frame 2700 A, providing a measurement of the UV upturn at a lookback time of approximately 4 Gyr. Surprisingly, the four elliptical galaxies observed show a range of UV upturn strength that is similar to that seen in nearby elliptical galaxies, with an equivalent 1550-V color ranging from 2.9-3.4 mag. Our result is inconsistent with some models for the UV upturn; other models are consistent only for a high redshift of formation (z_f >= 4).Comment: 4 pages, Latex. 1 figure. To appear in ApJL. Uses emulateapj.sty and apjfonts.sty. Revision includes minor ApJ edits & fixes typo

NIRCAM image simulations for NGST wavefront sensing

The Next Generation Space Telescope (NGST) will be a segmented, deployable, infrared-optimized 6.5m space telescope. Its active primary segments will be aligned, co-phased, and then fine-tuned in order to deliver image quality sufficient for the telescope's intended scientific goals. Wavefront sensing used to drive this tuning will come from the analysis of focussed and defocussed images taken with its near-IR science camera, NIRCAM. There is a pressing need to verify that this will be possible with the near-IR detectors that are still under development for NGST. We create simulated NIRCAM images to test the maintenance phase of this plan. Our simulations incorporate Poisson and electronics read noise, and are designed to be able to include various detector and electronics non-linearities. We present our first such simulation, using known or predicted properties of HAWAII HgCdTe focal plane array detectors. Detector effects characterized by the Independent Detector Testing Laboratory will be included as they become available. Simulating InSb detectors can also be done within this framework in future. We generate Point-Spread Functions (PSF's) for a segmented aperture geometry with various wavefront aberrations, and convolve this with typical galaxy backgrounds and stellar foregrounds. We then simulate up-the-ramp (MULTIACCUM in HST parlance) exposures with cosmic ray hits. We pass these images through the HST NICMOS `CALNICA' calibration task to filter out cosmic ray hits. The final images are to be fed to wavefront sensing software, in order to find the ranges of exposure times, filter bandpass, defocus, and calibration star magnitude required to keep the NGST image within its specifications

The early-type galaxies NGC 1407 and NGC 1400 - I: spatially resolved radial kinematics and surface photometry

This is the first paper of a series focused on investigating the star formation and evolutionary history of the two early-type galaxies NGC 1407 and NGC 1400. They are the two brightest galaxies of the NGC 1407 (or Eridanus-A) group, one of the 60 groups studied as part of the Group Evolution Multi-wavelength Study (GEMS). Here we present new high signal-to-noise long-slit spectroscopic data obtained at the ESO 3.6m telescope and high-resolution multi-band imaging data from the HST/ACS and wide-field imaging from Subaru Suprime-Cam. We spatially resolved integrated spectra out to 0.6 (NGC 1407) and 1.3 (NGC 1400) effective radii. The radial profiles of the kinematic parameters v(rot), sigma, h3 and h4 are measured. The surface brightness profiles are fitted to different galaxy light models and the colour distributions analysed. The multi-band images are modelled to derive isophotal shape parameters and residual galaxy images. The parameters from the surface brightness profile fitting are used to estimate the mass of the possible central supermassive black hole in NGC 1407. The galaxies are found to be rotationally supported and to have a flat core in the surface brightness profiles. Elliptical isophotes are observed at all radii and no fine structures are detected in the residual galaxy images. From our results we can also discard a possible interaction between NGC 1400, NGC 1407 and the group intergalactic medium. We estimate a mass of 1.03x10^9 M(sun) for the supermassive black hole in NGC 1407 galaxy.Comment: 11 pages, 6 tables, 6 figures, Accepted for publication in MNRA

NIRCAM image simulations for NGST wavefront sensing

The Next Generation Space Telescope (NGST) will be a segmented, deployable, infrared-optimized 6.5m space telescope. Its active primary segments will be aligned, co-phased, and then fine-tuned in order to deliver image quality sufficient for the telescope's intended scientific goals. Wavefront sensing used to drive this tuning will come from the analysis of focussed and defocussed images taken with its near-IR science camera, NIRCAM. There is a pressing need to verify that this will be possible with the near-IR detectors that are still under development for NGST. We create simulated NIRCAM images to test the maintenance phase of this plan. Our simulations incorporate Poisson and electronics read noise, and are designed to be able to include various detector and electronics non-linearities. We present our first such simulation, using known or predicted properties of HAWAII HgCdTe focal plane array detectors. Detector effects characterized by the Independent Detector Testing Laboratory will be included as they become available. Simulating InSb detectors can also be done within this framework in future. We generate Point-Spread Functions (PSF's) for a segmented aperture geometry with various wavefront aberrations, and convolve this with typical galaxy backgrounds and stellar foregrounds. We then simulate up-the-ramp (MULTIACCUM in HST parlance) exposures with cosmic ray hits. We pass these images through the HST NICMOS `CALNICA' calibration task to filter out cosmic ray hits. The final images are to be fed to wavefront sensing software, in order to find the ranges of exposure times, filter bandpass, defocus, and calibration star magnitude required to keep the NGST image within its specifications

Los Batanes: A trap for the Pyrenean wild goat during the Late Pleistocene (Spain)

Los Batanes cave (1025 m.a.s.l.) is a karstic system formed by pressure ducts, near the locality of Biescas in the Upper Gallego Valley (Huesca, Spain). Many fossil remains were retrieved from the cave sediments. The minimum sediment calendar age was determined to be 12.770 ± 60 BP. This date indicates that the deposit was formed before the Late Pleistocene-Early Holocene transition at the Pyrenees. Here we analyze the faunal assemblage of the site that is only conformed by remains of Pyrenean wild goat (Capra pyrenaica pyrenaica), which is a recently extinct subspecies of Iberian wild goat (C. pyrenaica). In the site, 1079 remains of Iberian wild goat have been recovered being one of the most numerous both in minimum number of individuals (MNI) and number of identified specimens (NISP) recovered until now in a natural trap in the Spanish Pyrenees. The population of Los Batanes shows a wide range of ages between juvenile and senile individuals and the MNI estimated from the number of right metatarsus is nine. The taphonomic features indicate that the cave acted as a trap for the goats which inhabited the vicinity of the cave. These goats probably stumbled and fell to the bottom of the pit and they could not get out, dying inside. Due to the origin of the accumulation numerous complete bones have been recovered. These fossil allow us to perform a biometric analysis that indicates that population of Los Batanes is in the range size of other goats from Late Pleistocene of Iberian Peninsula

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Unravelling the Scientific Debate on How to Address Wolf-Dog Hybridization in Europe

Anthropogenic hybridization is widely perceived as a threat to the conservation of biodiversity. Nevertheless, to date, relevant policy and management interventions are unresolved and highly convoluted. While this is due to the inherent complexity of the issue, we hereby hypothesize that a lack of agreement concerning management goals and approaches, within the scientific community, may explain the lack of social awareness on this phenomenon, and the absence of effective pressure on decision-makers. By focusing on wolf x dog hybridization in Europe, we hereby (a) assess the state of the art of issues on wolf x dog hybridization within the scientific community, (b) assess the conceptual bases for different viewpoints, and (c) provide a conceptual framework aiming at reducing the disagreements. We adopted the Delphi technique, involving a three-round iterative survey addressed to a selected sample of experts who published at Web of Science listed journals, in the last 10 years on wolf x dog hybridization and related topics. Consensus was reached that admixed individuals should always be defined according to their genetic profile, and that a reference threshold for admixture (i.e., q-value in assignment tests) should be formally adopted for their identification. To mitigate hybridization, experts agreed on adopting preventive, proactive and, when concerning small and recovering wolf populations, reactive interventions. Overall, experts' consensus waned as the issues addressed became increasingly practical, including the adoption of lethal removal. We suggest three non-mutually exclusive explanations for this trend: (i) value-laden viewpoints increasingly emerge when addressing practical issues, and are particularly diverging between experts with different disciplinary backgrounds (e.g., ecologists, geneticists); (ii) some experts prefer avoiding the risk of potentially giving carte blanche to wolf opponents to (illegally) remove wolves, based on the wolf x dog hybridization issue; (iii) room for subjective interpretation and opinions result from the paucity of data on the effectiveness of different management interventions. These results have management implications and reveal gaps in the knowledge on a wide spectrum of issues related not only to the management of anthropogenic hybridization, but also to the role of ethical values and real-world management concerns in the scientific debate

Backscatter From a Random Medium.

http://deepblue.lib.umich.edu/bitstream/2027.42/20967/2/rl0714.0001.001.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/20967/1/rl0714.0001.001.tx

Application of machine learning in the precise and cost-effective self-compensation of the thermal errors of CNC machine tools – a review

The current development of production engineering takes place through the innovative improvement of machine tools and machining processes at the constantly growing application of intelligent self-improvement functions. Machine learning opens up possibilities for machine tool self-improvement in real time. This paper discusses the state of knowledge relating to the application of machine learning for precise and cost-effective thermal error self-compensation. Data acquisition and processing, models and model learning and self-learning methods are also considered. Three highly effective error compensation systems (supported with machine learning) are analysed and conclusions and recommendations for future research are formulated