Search Publications

Metallicity has followed local gravitational potential of galaxies since z = 3
DOI: 10.1093/mnras/staa128 Bibcode: 2020MNRAS.492.4805M

Christensen, L.; Møller, P.

The MZ relation between stellar mass (M*) and metallicity (Z) of nearby galaxies has been described as both a global and local property, I.e. valid also on sub-galaxy scales. Here, we show that Z has remained a local property, following the gravitational potential, since z = 3. In absorption, the MZ relation has been well studied, and w…

2020 Monthly Notices of the Royal Astronomical Society
eHST 17
The Lyman Alpha Reference Sample. XI. Efficient turbulence-driven Lyα escape and an analysis of IR, CO, and [C II]158 µm
DOI: 10.1051/0004-6361/201936768 Bibcode: 2020A&A...644A..10P

Östlin, G.; Hayes, M.; Kunth, D. +8 more

Context. Lyman-α (Lyα) is the brightest emission line in star-forming galaxies. However, its interpretation in terms of physical properties is hampered by the resonant nature of Lyα photons. In order to remedy this complicated situation, the Lyman Alpha Reference Sample (LARS) was defined, enabling the study of Lyα production and escape mechanisms…

2020 Astronomy and Astrophysics
AKARI Herschel eHST 17
Near-infrared Spectroscopy of CK Vulpeculae: Revealing a Remarkably Powerful Blast from the Past
DOI: 10.3847/2041-8213/abc885 Bibcode: 2020ApJ...904L..23B

Gehrz, R. D.; Shahbandeh, M.; Eyres, S. P. S. +6 more

CK Vulpeculae (CK Vul), which erupted in AD 1670-71, was long considered to be a nova outburst; however, recent observations have required that alternative scenarios be considered. Long-slit infrared spectroscopy of a forbidden line of iron reported here has revealed high line-of-sight velocities (∼±900 km s-1) of the ansae at the tips …

2020 The Astrophysical Journal
Gaia 17
Failed prominence eruptions near 24 cycle maximum
DOI: 10.1093/mnras/staa896 Bibcode: 2020MNRAS.494.2166F

Filippov, B.

We analyse 16 failed filament eruptions observed near 24 solar cycle maximum from 2013 May to 2014 July. No significant rotation of filament spines is observed during the ascent in all studied failed eruptions, which does not support kink-instability mechanism of triggering the eruptions. We calculate potential magnetic field distributions in the …

2020 Monthly Notices of the Royal Astronomical Society
SOHO 17
Unveiling the Physical Conditions in NGC 6910
DOI: 10.3847/1538-4357/ab9122 Bibcode: 2020ApJ...896...29K

Sharma, Saurabh; Panwar, Neelam; Kaur, Harmeen +3 more

Deep and wide-field optical photometric observations along with multiwavelength archival data sets have been employed to study the physical properties of the cluster NGC 6910. The study also examines the impact of massive stars on their environment. The age, distance, and reddening of the cluster are estimated to be ∼4.5 Myr, 1.72 ± 0.08 kpc, and …

2020 The Astrophysical Journal
Gaia 17
Space Telescope and Optical Reverberation Mapping Project. XI. Disk-wind Characteristics and Contributions to the Very Broad Emission Lines of NGC 5548
DOI: 10.3847/1538-4357/ab9cb2 Bibcode: 2020ApJ...898..141D

Brandt, W. N.; Kriss, G. A.; Mehdipour, M. +22 more

In 2014 the NGC 5548 Space Telescope and Optical Reverberation Mapping campaign discovered a two-month anomaly when variations in the absorption and emission lines decorrelated from continuum variations. During this time the soft X-ray part of the intrinsic spectrum had been strongly absorbed by a line-of-sight (LOS) obscurer, which was interprete…

2020 The Astrophysical Journal
XMM-Newton eHST 17
The halo of M 105 and its group environment as traced by planetary nebula populations. I. Wide-field photometric survey of planetary nebulae in the Leo I group
DOI: 10.1051/0004-6361/202038009 Bibcode: 2020A&A...642A..46H

Freeman, K. C.; Gerhard, O.; Coccato, L. +6 more

Context. M 105 (NGC 3379) is an early-type galaxy in the Leo I group. The Leo I group is the nearest group that contains all main galaxy types and can thus be used as a benchmark to study the properties of the intra-group light (IGL) in low-mass groups.
Aims: We present a photometric survey of planetary nebulae (PNe) in the extended halo of t…

2020 Astronomy and Astrophysics
eHST 17
Jovian Auroral Ion Precipitation: X-Ray Production From Oxygen and Sulfur Precipitation
DOI: 10.1029/2019JA027007 Bibcode: 2020JGRA..12527007H

Cravens, T. E.; Mauk, B. H.; Dunn, W. R. +6 more

Many attempts have been made to model X-ray emission from both bremsstrahlung and ion precipitation into Jupiter's polar caps. Electron bremsstrahlung modeling has fallen short of producing the total overall power output observed by Earth-orbit-based X-ray observatories. Heavy ion precipitation was able to reproduce strong X-ray fluxes, but the pr…

2020 Journal of Geophysical Research (Space Physics)
XMM-Newton 17
Stellar atmospheric parameters of FGK-type stars from high-resolution optical and near-infrared CARMENES spectra
DOI: 10.1093/mnras/staa058 Bibcode: 2020MNRAS.492.5470M

Nagel, E.; Amado, P. J.; Caballero, J. A. +10 more

With the purpose of assessing classic spectroscopic methods on high-resolution and high signal-to-noise ratio spectra in the near-infrared wavelength region, we selected a sample of 65 F-, G-, and K-type stars observed with CARMENES, the new, ultra-stable, double-channel spectrograph at the 3.5 m Calar Alto telescope. We computed their stellar atm…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 17
Peculiarities in the Horizontal Branch Stars of Globular Cluster NGC 1851: Discovery of a Blue Straggler Companion to an EHB Star
DOI: 10.3847/1538-4357/abc173 Bibcode: 2020ApJ...905...44S

Yadav, R. K. S.; Sahu, Snehalata; Subramaniam, Annapurni +1 more

We present a study of far-UV (FUV) bright horizontal branch (HB) stars to understand the peculiarities seen in the HB sequence of the globular cluster NGC 1851, using ground- and space-based multiwavelength data. Optical and UV color-magnitude diagrams are used to classify HB stars and their membership from Hubble Space Telescope and Gaia DR2 data…

2020 The Astrophysical Journal
Gaia eHST 17