The First Detailed Abundances for M giants in Baade's Window from Infrared Spectroscopy

We report the first abundance analysis of 14 M giant stars in the Galactic bulge, based on R=25,000 infrared spectroscopy (1.5-1.8um) using NIRSPEC at the Keck II telescope. Because some of the bulge M giants reach high luminosities and have very late spectral type, it has been suggested that they are the progeny of only the most metal rich bulge stars, or possibly members of a younger bulge population. We find the iron abundance and composition of the M giants are similar to those of the K giants that have abundances determined from optical high resolution spectroscopy: =-0.190 +/- 0.020 with a 1-sigma dispersion of 0.08 +/- 0.015. Comparing our bulge M giants to a control sample of local disk M giants in the Solar vicinity, we find the bulge stars are enhanced in alpha elements at the level of +0.3 dex relative to the Solar composition stars, consistent with other studies of bulge globular clusters and field stars. This small sample shows no dependence of spectral type on metallicity, nor is there any indication that the M giants are the evolved members of a subset of the bulge population endowed with special characteristics such as relative youth or high metallicity. We also find low 12C/13C < 10, confirming the prsence of extra-mixing processes during the red gaint phase of evolutionComment: 19 pages, 7 figures, accepted for publication in the Astrophysical Journa

A near-infrared spectroscopic screening of the red giant populations in omega Centauri

Near-infrared spectra of 21 giants in omega Centauri, spanning the whole range of metallicities observed in this cluster, are presented. This work is part of a coordinated photometric and spectroscopic campaign in the optical and in the infrared, aimed at studying the complex stellar population of omega Centauri and understanding its formation and chemical evolution. By analyzing the several CO and OH molecular bands and atomic lines in the spectra of the selected giants, metal abundances and abundance ratios have been obtained. The existence of three major metallicity regimes at [Fe/H]=-1.6, -1.2 and [Fe/H]<-0.5 has been confirmed. The most metal-rich stars in our sample show a lower (if any) alpha-enhancement when compared to the more metal-poor components, suggesting that they should have formed in a medium significantly polluted by type Ia supernova ejecta. Isotopic carbon abundances have been also inferred, providing an average 13C/12C=4, which clearly indicates that extra-mixing processes occurred in the stellar interiors during the ascent on the Red Giant Branch.Comment: 22 pages, 7 .ps figures. aastex. Accepted for pubilcation in the Astrophysical Journa

High resolution infrared spectra of bulge globular clusters: Liller~1 and NGC 6553

Using the NIRSPEC spectrograph at Keck II, we have obtained echelle spectra covering the range 1.5-1.8um for 2 of the brightest giants in Liller 1 and NGC 6553, old metal rich globular clusters in the Galactic bulge. We use spectrum synthesis for the abundance analysis, and find [Fe/H]=-0.3 +/- 0.2 and [O/H]=+0.3 +/- 0.2 dex. The composition of the clusters is similar to that of field stars in the bulge and is consistent with a sceanrio in which the clusters formed early, with rapid enrichment. We have dificulty achieveing a good fit to the spectrum of NGC 6553 using either the low or the high values recently reported in the literature, unless unusually large, or no alpha-element enhancements are adopted, respectively.Comment: To appear in the Astronomical Journal, March 200

Detection of ionized gas in the globular cluster 47 Tucanae

We report the detection of ionized intracluster gas in the globular cluster 47 Tucanae. Pulsars in this cluster with a negative period derivative, which must lie in the distant half of the cluster, have significantly higher measured integrated electron column densities than the pulsars with a positive period derivative. We derive the plasma density within the central few pc of the cluster using two different methods which yield consistent values. Our best estimate of n_e = (0.067+-0.015)/cm^3 is about 100 times the free electron density of the ISM in the vicinity of 47 Tucanae, and the ionized gas is probably the dominant component of the intracluster medium.Comment: 5 pages, 3 included figures, accepted for publication by ApJ Letter

Verification of Knoop indenters with Gal-Indent optical system

Le normative internazionali ISO 4545-2 e 4545-3 per i test di durezza Knoop richiedono la verifica geometrica dei penetratori. Il laboratorio di durezza INRiM, in collaborazione con la Galileo-LTF®, ha sviluppato uno specifico sistema ottico di misurazione(commercializzato da Galileo-LTF® come Gal-Indent) , utilizzato per la verifica dei penetratori Vickers. Questo sistema è in grado di misurare i due angoli al vertice tra due facce opposte, i quattro angoli della base quadrangolare e l'angolo tra l'asse della piramide di diamante e l'asse del codolo del penetratore. Usando le misure degli angoli al vertice e della base come input di un appropriato modello geometrico, gli angoli al vertice tra spigoli opposti di penetratori Knoop, nominalmente di 172.5° e 130°, e l'angolo tra l'asse della piramide di diamante e l'asse del supporto del penetratore, nominalmente di 0°, possono essere verificati con un'incertezza estesa di 0.05°, come richiesto dalle normative. Il confronto tra le misure sperimentali eseguite con questo metodo su tre diversi penetratori Knoop, precedentemente verificati da un laboratorio accreditato tedesco, mostrano risultati compatibili, in termini di errore normalizzato.ISO 4545-2 and 4545-3 of Knoop hardness tests require the geometrical verification of the indenters. INRiM hardness laboratory, in cooperation with Galileo-LTF® has developed a specific optical measuring system (commercialized by Galileo-LTF® as Gal-Indent) which is addressed for the verification of Vickers indenters. This system is able to measure the two vertex angles between two opposite faces, the four angles of the quadrilateral base and the angle between the axis of the diamond pyramid and the axis of the indenter holder. Using the measured quantities of the vertex and base angles as inputs of a suitable geometrical model, the angles from the opposite edges at the vertex of Knoop indenters, nominally 172.5° and 130°, and the angle between the axis of the diamond pyramid and the axis of the indenter holder, nominally 0°, can be verified with an expanded uncertainty of 0.05°, as required by the relevant Standard. Comparison of experimental measurements performed on three different Knoop indenters, previously verified by a German accredited laboratory, shows compatible results in terms of normalized error

EURAMET key comparison between INRiM and UME in Vickers hardness scales (HV1 - HV30) - EURAMET.M.H-K1.b and c

This report describes the method and results of a bilateral EURAMET Key Comparison in Vickers hardness scales of two National Metrology Institutes (NMIs) of Italy and Turkey, INRiM and UME, respectively. The Pilot Laboratory (PL) is INRiM in the comparison in which one set of hardness reference blocks with three hardness levels for the Vickers Hardness scales of both HV1 and HV30 was used. The comparison was realized as planned in the Technical Protocol with some delay. The aim of this comparison is to link the UME measurement results to the CCM.H-K1.b.c through the PL (INRiM) as a participant of the CCM key comparison. The measurement results and uncertainty assessments declared by INRiM and UME are in consistency with each other and UME results are also in consistency with the CCM.H-K1.b.c Key Comparison Reference Values (KCRVs). The CCM.H-K1.b.c was realized during 2001 to 2003 to investigate the metrological equivalence of national standards among national metrology institutes (NMIs) within the CCM

Result analysis of EURAMET Vickers comparison between INRiM and UME (EURAMET.M.H-K1.b.c)

A bilateral key comparison between INRiM (National Metrology Institute of Italy) and TUBITAK UME (National Metrology Institute of Turkey) had been decided to be organized in the field of Hardness Metrology to determine the consistency of the national hardness standards in both countries realizing Vickers Hardness measurements in accordance with ISO 6507–1:2018 [1] and ISO 6507–3:2018 [2] standards. Widely used Vickers Hardness scales such as HV1 and HV30 constitute the scope of the comparison which was piloted by INRiM. In this paper the procedure and measurement results of the bilateral EURAMET key comparison between the two laboratories are explained

Preliminary results of EURAMET Rockwell comparison between INRiM and UME (EURAMET.M.H-S1.A.B.C)

A bilateral supplementary comparison between INRiM (National Metrology Institute of Italy) and UME (National Metrology Institute of Turkey) had been decided to be organized in the field of Hardness Metrology to determine the consistency of the national hardness standards in both countries realizing Rockwell Hardness measurements in accordance with ISO 6508-1:2016 [1] and ISO 6508-3:2015 [2] standards. In this paper the procedure and preliminary measurement results of the bilateral EURAMET supplementary comparison between the two laboratories are explained

Bilateral comparison in Rockwell C hardness scale between INRiM and GUM

This bilateral comparison in HRC is conducted in order to confirm the accuracy claimed by National Institute of Metrological Research in Italy (INRiM) and Central Office of Measures in Poland (GUM). Also, this study compares the difference of measurement results between two modernized deadweight-type Rockwell's hardness standard machines (HSMs) from GUM and primary hardness standard machine (PHSM) from INRiM. The hardness blocks of about 20 HRC, 35 HRC, 45 HRC, 50 HRC, 60 HRC and 65 HRC, which all have uniformity less then ±0.4 HRC according to EN ISO 6508-3, were used in this comparison

Result analysis of EURAMET Brinell comparison between INRiM, UME and PTB (EURAMET.M.H–S2.A.B)

A EURAMET supplementary comparison between INRiM (National Metrology Institute of Italy), UME (National Metrology Institute of Republic of Turkey) and PTB (National Metrology Institute of Germany) had been decided to be organized in the field of Hardness Metrology to determine the consistency of the national hardness standards in these three countries realizing Brinell Hardness measurements in accordance with ISO 6506–1:2014 [1] and ISO 6506–3:2014 [2] standards. Widely used Brinell Hardness scales such as HBW 1/30 and HBW 2.5/187.5 constitute the scope of the comparison. In this paper the procedure and comparison results are explained