Search Publications
Deriving the Interaction Point between a Coronal Mass Ejection and High-speed Stream: A Case Study
Dumbović, Mateja; Temmer, Manuela; Remeshan, Akshay Kumar
We analyze the interaction between an interplanetary coronal mass ejection (ICME) detected in situ at the L1 Lagrange point on 2016 October 12 with a trailing high-speed stream (HSS). We aim to estimate the region in the interplanetary (IP) space where the interaction happened/started using a combined observational-modeling approach. We use minimu…
Filament eruption by multiple reconnections
Liu, Y.; Chen, Y.; Schmieder, B. +5 more
Context. Filament eruption is a common phenomenon in solar activity, but the triggering mechanism is not well understood.
Aims: We focus our study on a filament eruption located in a complex nest of three active regions close to a coronal hole.
Methods: The filament eruption is observed at multiple wavelengths: by the Global Oscillation …
Coronal Modulation in the Ultra-fast Rotator LO Peg
Pandey, Jeewan Chandra; Singh, Gurpreet; Yadava, Umesh
We present coronal imaging of the ultra-fast rotator, LO Peg, using the X-ray observations from XMM-Newton. The X-ray light curves show one strong flare at the end of observation, as reported in an earlier study. On removal of flaring events, the quiescent state light curve shows rotational modulations, which are modelled using a maximum likelihoo…
New stellar age estimates using SPInS based on Gaia DR3 photometry and LAMOST DR8 abundances
Reese, D. R.; Casamiquela, L.; Anders, F. +8 more
Context. Reliable stellar age estimates are fundamental for testing several problems in modern astrophysics, in particular since they set the timescales of Galactic dynamical and chemical evolution. Aims. In this study, we determine ages using only Gaia DR3 photometry and parallaxes, in combination with interstellar extinction maps, and spectrosco…
ESO 137–001: A jellyfish galaxy model
Boselli, A.; Sun, M.; Fossati, M. +2 more
Ram-pressure stripping of the spiral galaxy ESO 137‑001 within the highly dynamical intracluster medium (ICM) of the Norma cluster lead to spectacular extraplanar CO, optical, Hα, UV, and X-ray emission. The Hα and X-ray tails extend up to 80 kpc from the galactic disk. We present dynamical simulations of the ram-pressure stripping event, and inve…
Modelling stellar variability in archival HARPS data: I - Rotation and activity properties with multidimensional Gaussian processes
Aigrain, Suzanne; Mortier, Annelies; Klein, Baptiste +4 more
Although instruments for measuring the radial velocities (RVs) of stars now routinely reach sub-metre per second accuracy, the detection of low-mass planets is still very challenging. The rotational modulation and evolution of spots and/or faculae can induce variations in the RVs at the level of a few m s-1 in Sun-like stars. To overcom…
The Black Hole Mass and Photometric Components of NGC 4826
Gebhardt, Karl; Kormendy, John; Lauer, Tod R. +6 more
We present infrared photometry and Hubble Space Telescope imaging and spectroscopy of the Sab galaxy NGC 4826. Schwarzschild dynamical modeling is used to measure its central black hole mass M. Photometric decomposition is used to enable a comparison of M to published scaling relations between black hole masses and properties of host bulges. This …
Improving the Spectral Resolution and Wavelength Scale of SDO/EVE MEGS-A Flare Observations
Chamberlin, Phillip; Gonzalez, Gabriela; Herde, Vicki
The Extreme ultraviolet Variability Experiment (EVE) is one of three instruments onboard the Solar Dynamics Observatory (SDO). This paper focuses on using the "A" channel on the Multiple EUV Grating Spectrographs (MEGS-A) on EVE, which measures wavelengths of 5 – 37 nm, to improve the wavelength scale accuracy and spectral resolution during solar …
Modifications of astrophysical ices induced by cosmic rays. I. Water, carbon monoxide, and methanol mixtures
da Silveira, E. F.; Rothard, H.; Domaracka, A. +3 more
Aims: Astrophysical ices on dust grain mantles in the interstellar medium (ISM) and dense circumstellar envelopes (CSEs) are continuously exposed to galactic cosmic rays (GCRs). In a laboratory setting, we studied the physical and chemical modifications of ice layers induced by energetic heavy ions as GCR analogues. The ice layers used have a…
The TESS-Keck Survey. XXII. A Sub-Neptune Orbiting TOI-1437
Barclay, Thomas; Batalha, Natalie M.; Mayo, Andrew W. +40 more
Exoplanet discoveries have revealed a dramatic diversity of planet sizes across a vast array of orbital architectures. Sub-Neptunes are of particular interest; due to their absence in our own solar system, we rely on demographics of exoplanets to better understand their bulk composition and formation scenarios. Here, we present the discovery and c…