Search Publications

IRIS Si IV Line Profiles at Flare Ribbons as Indications of Chromospheric Condensation
DOI: 10.3847/1538-4357/ab9014 Bibcode: 2020ApJ...896..154Y

Ding, M. D.; Li, Y.; Li, D. +3 more

We present temporal variations of the Si IV line profiles at the flare ribbons in three solar flares observed by the Interface Region Imaging Spectrograph. In the M1.1 flare on 2014 September 6 and the X1.6 flare on 2014 September 10, the Si IV line profiles evolve from wholly redshifted to red-wing enhanced with the flare development. However, in…

2020 The Astrophysical Journal
IRIS 22
A plague of magnetic spots among the hot stars of globular clusters
DOI: 10.1038/s41550-020-1113-4 Bibcode: 2020NatAs...4.1092M

Gullieuszik, M.; Milone, A. P.; Stetson, P. B. +15 more

For more than six decades, the quest to understand the formation of hot (about 20,000-30,000 K) extreme horizontal branch (EHB) stars in Galactic globular clusters has remained one of the most elusive in stellar evolutionary theory. Here we report on two discoveries that challenge the idea of the stable luminosity of EHB stars. The first mode of E…

2020 Nature Astronomy
eHST 22
Investigating the growing population of massive quiescent galaxies at cosmic noon
DOI: 10.1093/mnras/staa3167 Bibcode: 2020MNRAS.499.4239S

Papovich, Casey; Finkelstein, Steven L.; Stevans, Matthew L. +10 more

We explore the build-up of quiescent galaxies using a sample of 28 469 massive (M ≥ 1011 M) galaxies at redshifts 1.5 < $z$ < 3.0, drawn from a 17.5 deg2 area (0.33 Gpc3 comoving volume at these redshifts). This allows for a robust study of the quiescent fraction as a function of mass …

2020 Monthly Notices of the Royal Astronomical Society
Herschel 22
Nature of Compton-thick Active Galactic Nuclei in "Nonmerging" Luminous Infrared Galaxies UGC 2608 and NGC 5135 Revealed with Broadband X-Ray Spectroscopy
DOI: 10.3847/1538-4357/ab94b1 Bibcode: 2020ApJ...897..107Y

Imanishi, Masatoshi; Tanimoto, Atsushi; Ueda, Yoshihiro +4 more

We have analyzed the broadband X-ray spectra of active galactic nuclei (AGNs) in two "nonmerging" luminous infrared galaxies (LIRGs), UGC 2608 and NGC 5135, utilizing the data of Nuclear Spectroscopic Telescope Array, Suzaku, XMM-Newton, and Chandra. Applying the X-ray clumpy-torus model (XCLUMPY), we find that both sources have similar spectra ch…

2020 The Astrophysical Journal
Suzaku XMM-Newton 22
SPIDERS: overview of the X-ray galaxy cluster follow-up and the final spectroscopic data release
DOI: 10.1093/mnras/staa2066 Bibcode: 2020MNRAS.497.3976C

Finoguenov, A.; Salvato, M.; Merloni, A. +19 more

SPIDERS (The SPectroscopic IDentification of eROSITA Sources) is a large spectroscopic programme for X-ray selected galaxy clusters as part of the Sloan Digital Sky Survey-IV (SDSS-IV). We describe the final data set in the context of SDSS Data Release 16 (DR16): the survey overall characteristics, final targeting strategies, achieved completeness…

2020 Monthly Notices of the Royal Astronomical Society
XMM-Newton 22
V1460 Her: a fast spinning white dwarf accreting from an evolved donor star
DOI: 10.1093/mnras/staa2676 Bibcode: 2020MNRAS.499..149A

Thorstensen, John R.; Gänsicke, B. T.; Pala, A. F. +6 more

We present time-resolved optical and ultraviolet (UV) spectroscopy and photometry of V1460 Her, an eclipsing cataclysmic variable with a 4.99-h orbital period and an overluminous K5-type donor star. The optical spectra show emission lines from an accretion disc along with absorption lines from the donor. We use these to measure radial velocities, …

2020 Monthly Notices of the Royal Astronomical Society
eHST 22
HST/WFC3 grism observations of z ∼ 1 clusters: evidence for evolution in the mass-size relation of quiescent galaxies from post-starburst galaxies
DOI: 10.1093/mnras/staa610 Bibcode: 2020MNRAS.493.6011M

Demarco, R.; Brammer, G. B.; Matharu, J. +10 more

Minor mergers have been proposed as the driving mechanism for the size growth of quiescent galaxies with decreasing redshift. The process whereby large star-forming galaxies quench and join the quiescent population at the large size end has also been suggested as an explanation for this size growth. Given the clear association of quenching with cl…

2020 Monthly Notices of the Royal Astronomical Society
eHST 22
A complete view of the outskirts of the Coma cluster
DOI: 10.1093/mnras/staa2203 Bibcode: 2020MNRAS.497.3204M

Walker, S. A.; Mirakhor, M. S.

We present a new extended XMM-Newton mosaic of the nearby Coma cluster, which covers the cluster out to the virial radius with nearly complete azimuthal coverage. This large mosaic is combined with the Planck Sunyaev Zel'dovich effect observations to recover the thermodynamic properties of the intracluster medium in an azimuthally averaged profile…

2020 Monthly Notices of the Royal Astronomical Society
XMM-Newton 22
Updated theoretical period-age and period-age-colour relations for Galactic Classical Cepheids: an application to the Gaia DR2 sample
DOI: 10.1093/mnras/staa1834 Bibcode: 2020MNRAS.496.5039D

Marconi, Marcella; Molinaro, Roberto; Ripepi, Vincenzo +4 more

Updated evolutionary and pulsational model predictions are combined in order to interpret the properties of Galactic Classical Cepheids in the Gaia Data Release 2. In particular, the location of the instability strip boundaries and the analytical relations connecting pulsation periods to the intrinsic stellar parameters are combined with evolution…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 22
Lyman Continuum Escape Fraction from Low-mass Starbursts at z = 1.3
DOI: 10.3847/1538-4357/abbd43 Bibcode: 2020ApJ...904...59A

Teplitz, Harry I.; Scarlata, Claudia; Henry, Alaina +8 more

We present a new constraint on the Lyman continuum (LyC) escape fraction at $z\sim 1.3$ . We obtain deep, high sensitivity far-UV imaging with the Advanced Camera for Surveys Solar Blind Channel on the Hubble Space Telescope, targeting 11 star-forming galaxies at 1.2 < z < 1.4. The galaxies are selected from the 3D-HST survey to have high Hα…

2020 The Astrophysical Journal
eHST 22