Discovery of the first methanol (CH3OH) maser in the Andromeda galaxy (M31)

We present the first detection of a 6.7 GHz Class II methanol (CH3OH) maser in the Andromeda galaxy (M31). The CH3OH maser was found in a Very Large Array (VLA) survey during the fall of 2009. We have confirmed the methanol maser with the new Expanded VLA (EVLA), in operation since March 2010, but were unsuccessful in detecting a water maser at this location. A direct application for this methanol maser is the determination of the proper motion of M31, such as was obtained with water masers in M33 and IC10 previously. Unraveling the three-dimensional velocity of M31 would solve for the biggest unknown in the modeling of the dynamics and evolution of the Local Group of galaxies.Comment: Letter, accepted by ApJ

Is there an ethics of algorithms?

We argue that some algorithms are value-laden, and that two or more persons who accept different value-judgments may have a rational reason to design such algorithms differently. We exemplify our claim by discussing a set of algorithms used in medical image analysis: In these algorithms it is often necessary to set certain thresholds for whether e.g. a cell should count as diseased or not, and the chosen threshold will partly depend on the software designer’s preference between avoiding false positives and false negatives. This preference ultimately depends on a number of value-judgments. In the last section of the paper we discuss some general principles for dealing with ethical issues in algorithm-design

Carbon-rich dust production in metal-poor galaxies in the Local Group

We have observed a sample of 19 carbon stars in the Sculptor, Carina, Fornax, and Leo I dwarf spheroidal galaxies with the Infrared Spectrograph on the Spitzer Space Telescope. The spectra show significant quantities of dust around the carbon stars in Sculptor, Fornax, and Leo I, but little in Carina. Previous comparisons of carbon stars with similar pulsation properties in the Galaxy and the Magellanic Clouds revealed no evidence that metallicity affected the production of dust by carbon stars. However, the more metal-poor stars in the current sample appear to be generating less dust. These data extend two known trends to lower metallicities. In more metal-poor samples, the SiC dust emission weakens, while the acetylene absorption strengthens. The bolometric magnitudes and infrared spectral properties of the carbon stars in Fornax are consistent with metallicities more similar to carbon stars in the Magellanic Clouds than in the other dwarf spheroidals in our sample. A study of the carbon budget in these stars reinforces previous considerations that the dredge-up of sufficient quantities of carbon from the stellar cores may trigger the final superwind phase, ending a star's lifetime on the asymptotic giant branch.Comment: ApJ, in press, 21 pages, 12 figures. Replaced Fig 12, corrected two reference

Association Between Serum Carnosinase Concentration and Activity and Renal Function Impairment in a Type-2 Diabetes Cohort

Introduction: Genetic studies have identified associations of carnosinase 1 (CN1) polymorphisms with diabetic kidney disease (DKD). However, CN1 levels and activities have not been assessed as diagnostic or prognostic markers of DKD in cohorts of patients with type 2 diabetes (T2D).Methods: We established high-throughput, automated CN1 activity and concentration assays using robotic systems. Using these methods, we determined baseline serum CN1 levels and activity in a T2D cohort with 970 patients with no or only mild renal impairment. The patients were followed for a mean of 1.2 years. Baseline serum CN1 concentration and activity were assessed as predictors of renal function impairment and incident albuminuria during follow up.Results: CN1 concentration was significantly associated with age, gender and estimated glomerular filtration rate (eGFR) at baseline. CN1 activity was significantly associated with glycated hemoglobin A1c (HbA1c) and eGFR. Serum CN1 at baseline was associated with eGFR decline and predicted renal function impairment and incident albuminuria during the follow-up.Discussion: Baseline serum CN1 levels were associated with presence and progression of renal function decline in a cohort of T2D patients. Confirmation in larger cohorts with longer follow-up observation periods will be required to fully establish CN1 as a biomarker of DKD

Tycho 2 stars with infrared excess in the MSX Point Source Catalogue

Stars of all evolutionary phases have been found to have excess infrared emission due to the presence of circumstellar material. To identify such stars, we have positionally correlated the infrared MSX point source catalogue and the Tycho 2 optical catalogue. A near/mid infrared colour criteria has been developed to select infrared excess stars. The search yielded 1938 excess stars, over half (979) have never previously been detected by IRAS. The excess stars were found to be young objects such as Herbig Ae/Be and Be stars, and evolved objects such as OH/IR and carbon stars. A number of B type excess stars were also discovered whose infrared colours could not be readily explained by known catalogued objects.Comment: Added Comment: 16 pages, 9 figures, accepted for publication in MNRA

Nuclear and Extended Spectra of NGC 1068 - I: Hints from Near-Infrared Spectroscopy

We report the first simultaneous zJHK spectroscopy on the archetypical Seyfert 2 Galaxy NGC 1068 covering the wavelength region 0.9 to 2.4 micron. The slit, aligned in the NS direction and centred in the optical nucleus, maps a region 300 pc in radius at sub-arcsec resolution, with a spectral resolving power of 360 km s^-1. This configuration allow us to study the physical properties of the nuclear gas including that of the north side of the ionization cone, map the strong excess of continuum emission in the K-band and attributed to dust and study the variations, both in flux and profile, in the emission lines. Our results show that (1) Mid- to low-ionization emission lines are splitted into two components, whose relative strengths vary with the position along the slit and seem to be correlated with the jet. (2) The coronal lines are single-peaked and are detected only in the central few hundred of parsecs from the nucleus. (3) The absorption lines indicate the presence of intermediate age stellar population, which might be a significant contributor to the continuum in the NIR spectra. (4) Through some simple photoionization models we find photoionization as the main mechanism powering the emitting gas. (5) Calculations using stellar features point to a mass concentration inside the 100 - 200 pc of about 10^10 solar masses.Comment: 19 Pages, 14 figures. Accepted for publication in MNRA