Outputs (286)

RAVE stars in K2: I. Improving RAVE red giants spectroscopy using asteroseismology from K2 Campaign 1 (2017)
Journal Article
Valentini, M., Chiappini, C., Davies, G. R., Elsworth, Y. P., Mosser, B., Lund, M. N., Miglio, A., Chaplin, W. J., Rodrigues, T. S., Boeche, C., Steinmetz, M., Matijevič, G., Kordopatis, G., Bland-Hawthorn, J., Munari, U., Bienaymé, O., Freeman, K. C., Gibson, B. K., Gilmore, G., Grebel, E. K., …Mott, A. (2017). RAVE stars in K2: I. Improving RAVE red giants spectroscopy using asteroseismology from K2 Campaign 1. Astronomy and Astrophysics, 600, A66. https://doi.org/10.1051/0004-6361/201629701

© 2017 ESO. We present a set of 87 RAVE stars with detected solar like oscillations, observed during Campaign 1 of the K2 mission (RAVE K2-C1 sample). This data set provides a useful benchmark for testing the gravities provided in RAVE data release 4... Read More about RAVE stars in K2: I. Improving RAVE red giants spectroscopy using asteroseismology from K2 Campaign 1.

On the abundance of extreme voids II : a survey of void mass functions (2017)
Journal Article
Chongchitnan, S., & Hunt, M. (2017). On the abundance of extreme voids II : a survey of void mass functions. Journal of cosmology and astroparticle physics, 2017(03), Article 049. https://doi.org/10.1088/1475-7516/2017/03/049

The abundance of cosmic voids can be described by an analogue of halo mass functions for galaxy clusters. In this work, we explore a number of void mass functions: from those based on excursion-set theory to new mass functions obtained by modifying h... Read More about On the abundance of extreme voids II : a survey of void mass functions.

A chemical signature from fast-rotating low-metallicity massive stars: ROA 276 in ω Centauri (2017)
Journal Article
Yong, D., Norris, J. E., Da Costa, G. S., Stanford, L. M., Karakas, A. I., Shingles, L. J., Hirschi, R., & Pignatari, M. (2017). A chemical signature from fast-rotating low-metallicity massive stars: ROA 276 in ω Centauri. The Astrophysical journal, 837(2), 176. https://doi.org/10.3847/1538-4357/aa6250

© 2017. The American Astronomical Society. All rights reserved. We present a chemical abundance analysis of a metal-poor star, ROA 276, in the stellar system ω Centauri. We confirm that this star has an unusually high [Sr/Ba] abundance ratio. Additio... Read More about A chemical signature from fast-rotating low-metallicity massive stars: ROA 276 in ω Centauri.

Galaxy chemical evolution models: The role of molecular gas formation (2017)
Journal Article
Mollá, M., Díaz, Á. I., Ascasibar, Y., & Gibson, B. K. (2017). Galaxy chemical evolution models: The role of molecular gas formation. Monthly notices of the Royal Astronomical Society, 468(1), 305-318. https://doi.org/10.1093/mnras/stx419

In our classical grid of multiphase chemical evolution models, star formation in the disc occurs in two steps: first, molecular gas forms, and then stars are created by cloud-cloud collisions or interactions of massive stars with the surrounding mole... Read More about Galaxy chemical evolution models: The role of molecular gas formation.

Neutron spectroscopy of 26 Mg states: Constraining the stellar neutron source 22 Ne( α , n ) 25 Mg (2017)
Journal Article
Kivel, N., Karadimos, D., Käppeler, F., Kadi, Y., Krtička, M., Kopecky, S., Kokkoris, M., Koehler, P., Leal-Cidoncha, E., Langer, C., Lampoudis, C., Kroll, J., Losito, R., Lo Meo, S., Leeb, H., Lederer, C., Mastromarco, M., Martínez, T., Marganiec, J., Manousos, A., …Schillebeeckx, P. (2017). Neutron spectroscopy of 26 Mg states: Constraining the stellar neutron source 22 Ne( α , n ) 25 Mg. Physics letters. B, 768, 1-6. https://doi.org/10.1016/j.physletb.2017.02.025

This work reports on accurate, high-resolution measurements of the 25 Mg(n,γ) 26 Mg and 25 Mg(n,tot) cross sections in the neutron energy range from thermal to about 300 keV, leading to a significantly improved 25 Mg(n,γ) 26 Mg parametrization. The r... Read More about Neutron spectroscopy of 26 Mg states: Constraining the stellar neutron source 22 Ne( α , n ) 25 Mg.

NanoSIMS isotope studies of rare types of presolar silicon carbide grains from the Murchison meteorite: Implications for supernova models and the role of 14C (2017)
Journal Article
Hoppe, P., Pignatari, M., Kodolányi, J., Gröner, E., & Amari, S. (2018). NanoSIMS isotope studies of rare types of presolar silicon carbide grains from the Murchison meteorite: Implications for supernova models and the role of 14C. Geochimica et cosmochimica acta, 221, 182-199. https://doi.org/10.1016/j.gca.2017.01.051

© 2017 Elsevier Ltd. We have conducted a NanoSIMS ion imaging survey of about 1800 presolar silicon carbide (SiC) grains from the Murchison meteorite. A total of 21 supernova (SN) X grains, two SN C grains, and two putative nova grains were identifie... Read More about NanoSIMS isotope studies of rare types of presolar silicon carbide grains from the Murchison meteorite: Implications for supernova models and the role of 14C.

Stellar (n,γ) cross sections of ²³Na (2017)
Journal Article
Uberseder, E., Heil, M., Käppeler, F., Lederer, C., Mengoni, A., Bisterzo, S., Pignatari, M., & Wiescher, M. (2017). Stellar (n,γ) cross sections of ²³Na. Physical Review C, 95(2), 025803. https://doi.org/10.1103/PhysRevC.95.025803

The cross section of the ²³Na(n,γ)²⁴Na reaction has been measured via the activation method at the Karlsruhe 3.7 MV Van de Graaff accelerator. NaCl samples were exposed to quasistellar neutron spectra at kT = 5.1 and 25 keV produced via the ¹⁸O(p,n)¹... Read More about Stellar (n,γ) cross sections of ²³Na.

Chandra and JVLA Observations of HST Frontier Fields Cluster MACS J0717.5+3745 (2017)
Journal Article
van Weeren, R. J., Ogrean, G. A., Jones, C., Forman, W. R., Andrade-Santos, F., Pearce, C. J. J., Bonafede, A., Brüggen, M., Bulbul, E., Clarke, T. E., Churazov, E., David, L., Dawson, W. A., Donahue, M., Goulding, A., Kraft, R. P., Mason, B., Merten, J., Mroczkowski, T., Nulsen, P. E. J., …Zitrin, A. (2017). Chandra and JVLA Observations of HST Frontier Fields Cluster MACS J0717.5+3745. The Astrophysical journal, 835(2), 197. https://doi.org/10.3847/1538-4357/835/2/197

To investigate the relationship between thermal and non-thermal components in merger galaxy clusters, we present deep JVLA and Chandra observations of the HST Frontier Fields cluster MACS J0717.5+3745. The Chandra image shows a complex merger event,... Read More about Chandra and JVLA Observations of HST Frontier Fields Cluster MACS J0717.5+3745.

A study of central galaxy rotation with stellar mass and environment (2017)
Journal Article
Lara-Lopez, M. A., Lopez-Sanchez, A. R., Oliva-Altamirano, P., Brough, S., Tran, K.-V., Jimmy, Miller, C., Bremer, M. N., Phillipps, S., Sharp, R., Colless, M., Lara-López, M. A., López-Sánchez, Á. R., Pimbblet, K., Kafle, P. R., & Couch, W. J. (2017). A study of central galaxy rotation with stellar mass and environment. The Astronomical journal, 153(2), 89. https://doi.org/10.3847/1538-3881/153/2/89

© 2017. The American Astronomical Society. All rights reserved. We present a pilot analysis of the influence of galaxy stellar mass and cluster environment on the probability of slow rotation in 22 central galaxies at mean redshift z = 0.07. This inc... Read More about A study of central galaxy rotation with stellar mass and environment.

Chromospherically Active Stars in the RAVE Survey. II. Young dwarfs in the Solar neighborhood (2017)
Journal Article
Žerjal, M., Zwitter, T., Matijevič, G., Grebel, E. K., Kordopatis, G., Munari, U., Seabroke, G., Steinmetz, M., Wojno, J., Bienaymé, O., Bland-Hawthorn, J., Conrad, C., Freeman, K. C., Gibson, B. K., Gilmore, G., Kunder, A., Navarro, J., Parker, Q. A., Reid, W., Siviero, A., …Wyse, R. F. G. (2017). Chromospherically Active Stars in the RAVE Survey. II. Young dwarfs in the Solar neighborhood. The Astrophysical journal, 835(1), 61. https://doi.org/10.3847/1538-4357/835/1/61

A large sample of over 38,000 chromospherically active candidate solar-like stars and cooler dwarfs from the RAVE survey is addressed in this paper. An improved activity identification with respect to the previous study was introduced to build a cata... Read More about Chromospherically Active Stars in the RAVE Survey. II. Young dwarfs in the Solar neighborhood.

Capturing the 3D motion of an infalling galaxy via fluid dynamics (2017)
Journal Article
Su, Y., Kraft, R. P., Nulsen, P. E. J., Roediger, E., Forman, W. R., Churazov, E., Randall, S. W., Jones, C., & Machacek, M. E. (2017). Capturing the 3D motion of an infalling galaxy via fluid dynamics. The Astrophysical journal, 835(1), 19. https://doi.org/10.3847/1538-4357/835/1/19

The Fornax Cluster is the nearest galaxy cluster in the southern sky. NGC 1404 is a bright elliptical galaxy falling through the intracluster medium of the Fornax Cluster. The sharp leading edge of NGC 1404 forms a classical "cold front" that separat... Read More about Capturing the 3D motion of an infalling galaxy via fluid dynamics.

i-process Nucleosynthesis and Mass Retention Efficiency in He-shell Flash Evolution of Rapidly Accreting White Dwarfs (2017)
Journal Article
Denissenkov, P. A., Herwig, F., Battino, U., Ritter, C., Pignatari, M., Jones, S., & Paxton, B. (2017). i-process Nucleosynthesis and Mass Retention Efficiency in He-shell Flash Evolution of Rapidly Accreting White Dwarfs. Astrophysical journal. Letters, 834(2), L10. https://doi.org/10.3847/2041-8213/834/2/l10

© 2017. The American Astronomical Society. All rights reserved. Based on stellar evolution simulations, we demonstrate that rapidly accreting white dwarfs (WDs) in close binary systems are an astrophysical site for the intermediate neutron-capture pr... Read More about i-process Nucleosynthesis and Mass Retention Efficiency in He-shell Flash Evolution of Rapidly Accreting White Dwarfs.

Deep Chandra observations of NGC 1404 : cluster plasma physics revealed by an infalling early-type galaxy (2017)
Journal Article
Kraft, R. P., Forman, W. R., Randall, S. W., Machacek, M. E., Roediger, E., Churazov, E., Forman, W., Jones, C., Kraft, R., Machacek, M., Nulsen, P., Randall, S., & Su, Y. (2017). Deep Chandra observations of NGC 1404 : cluster plasma physics revealed by an infalling early-type galaxy. The Astrophysical journal, 834(1), 74. https://doi.org/10.3847/1538-4357/834/1/74

The intracluster medium (ICM), as a magnetized and highly ionized fluid, provides an ideal laboratory to study plasma physics under extreme conditions that cannot yet be achieved on Earth. NGC 1404 is a bright elliptical galaxy that is being gas stri... Read More about Deep Chandra observations of NGC 1404 : cluster plasma physics revealed by an infalling early-type galaxy.

Evidence for HI replenishment in massive galaxies through gas accretion from the cosmic web (2016)
Journal Article
Kleiner, D., Pimbblet, K. A., Heath Jones, D., Koribalski, B. S., & Serra, P. (2017). Evidence for HI replenishment in massive galaxies through gas accretion from the cosmic web. Monthly notices of the Royal Astronomical Society, 466(4), 4692-4710. https://doi.org/10.1093/mnras/stw3328

We examine the H i -to-stellar mass ratio (H i fraction) for galaxies near filament backbones within the nearby Universe (d < 181 Mpc). This work uses the 6 degree Field Galaxy Survey (6dFGS) and the Discrete Persistent Structures Extractor (DisPerSE... Read More about Evidence for HI replenishment in massive galaxies through gas accretion from the cosmic web.

Galaxy and Mass Assembly (GAMA): active galactic nuclei in pairs of galaxies (2016)
Journal Article
Gordon, Y. A., Owers, M. S., Pimbblet, K. A., Croom, S. M., Alpaslan, M., Baldry, I. K., Brough, S., Brown, M. J., Cluver, M. E., Conselice, C. J., Davies, L. J., Holwerda, B. W., Hopkins, A. M., Gunawardhana, M. L., Loveday, J., Taylor, E. N., & Wang, L. (2017). Galaxy and Mass Assembly (GAMA): active galactic nuclei in pairs of galaxies. Monthly notices of the Royal Astronomical Society, 465(3), 2671-2686. https://doi.org/10.1093/mnras/stw2925

There exist conflicting observations on whether or not the environment of broad and narrow line AGN differ and this consequently questions the validity of the AGN unification model. The high spectroscopic completeness of the GAMA survey makes it idea... Read More about Galaxy and Mass Assembly (GAMA): active galactic nuclei in pairs of galaxies.

Amine catalysis for the organocatalytic diboration of challenging alkenes (2016)
Journal Article
Farre, A., Soares, K., Briggs, R. A., Balanta, A., Benoit, D. M., & Bonet, A. (2016). Amine catalysis for the organocatalytic diboration of challenging alkenes. Chemistry: a European journal, 22(49), 17552-17556. https://doi.org/10.1002/chem.201603979

© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim The generation of in situ sp 2 –sp 3 diboron adducts has revolutionised the synthesis of organoboranes. Organocatalytic diboration reactions have represented a milestone in terms of unpredictable re... Read More about Amine catalysis for the organocatalytic diboration of challenging alkenes.

Measuring the 2D baryon acoustic oscillation signal of galaxies in WiggleZ: cosmological constraints (2016)
Journal Article
Hinton, S. R., Kazin, E., Davis, T. M., Blake, C., Brough, S., Colless, M., Couch, W. J., Drinkwater, M. J., Glazebrook, K., Jurek, R. J., Parkinson, D., Pimbblet, K. A., Poole, G. B., Pracy, M., & Woods, D. (2017). Measuring the 2D baryon acoustic oscillation signal of galaxies in WiggleZ: cosmological constraints. Monthly notices of the Royal Astronomical Society, 464(4), 4807-4822. https://doi.org/10.1093/mnras/stw2725

© 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. We present results from the 2D anisotropic baryon acoustic oscillation (BAO) signal present in the final data set from the WiggleZ Dark Energy Surve... Read More about Measuring the 2D baryon acoustic oscillation signal of galaxies in WiggleZ: cosmological constraints.

HI4PI: A full-sky Hi survey based on EBHIS and GASS (2016)
Journal Article
Ben Bekhti, N., Flöer, L., Keller, R., Kerp, J., Lenz, D., Winkel, B., Bailin, J., Calabretta, M. R., Dedes, L., Ford, H. A., Gibson, B. K., Haud, U., Janowiecki, S., Kalberla, P. M. W., Lockman, F. J., McClure-Griffiths, N. M., Murphy, T., Nakanishi, H., Pisano, D. J., Staveley-Smith, L., & HI4PI Collaboration:. (2016). HI4PI: A full-sky Hi survey based on EBHIS and GASS. Astronomy and Astrophysics, 594, A116. https://doi.org/10.1051/0004-6361/201629178

© 2016 ESO. Context. Measurement of the Galactic neutral atomic hydrogen (H i) column density, NH i, and brightness temperatures, TB, is of high scientific value for a broad range of astrophysical disciplines. In the past two decades, one of the most... Read More about HI4PI: A full-sky Hi survey based on EBHIS and GASS.

Looking for imprints of the first stellar generations in metal-poor bulge field stars (2016)
Journal Article
Chiappini, C., Freeman, K., Ness, M., Depagne, E., Cantelli, E., Hirschi, R., Frischknecht, U., Maeder, A., Pignatari, M., Barbuy, B., Cantelli, E. W. C., Chiappini, C., Depagne, É., Freeman, K., Frischknecht, U., Hirschi, R., Maeder, A., Meynet, G., Ness, M., & Siqueira-Mello, C. (2016). Looking for imprints of the first stellar generations in metal-poor bulge field stars. Astronomy and Astrophysics, 593, A79-1-A79-16. https://doi.org/10.1051/0004-6361/201628104

© 2016 ESO. Context. Efforts to look for signatures of the first stars have concentrated on metal-poor halo objects. However, the low end of the bulge metallicity distribution has been shown to host some of the oldest objects in the Milky Way and hen... Read More about Looking for imprints of the first stellar generations in metal-poor bulge field stars.

Impacts of a flaring star-forming disc and stellar radial mixing on the vertical metallicity gradient (2016)
Journal Article
Kawata, D., Grand, R. J. J., Gibson, B. K., Casagrande, L., Hunt, J. A. S., & Brook, C. B. (2017). Impacts of a flaring star-forming disc and stellar radial mixing on the vertical metallicity gradient. Monthly notices of the Royal Astronomical Society, 464(1), 702-712. https://doi.org/10.1093/mnras/stw2363

Using idealized N-body simulations of a Milky Way-sized disc galaxy, we qualitatively study how the metallicity distributions of the thin disc star particles are modified by the formation of the bar and spiral arm structures. The thin disc in our num... Read More about Impacts of a flaring star-forming disc and stellar radial mixing on the vertical metallicity gradient.