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Related papers: iSTARMOD: A Python Code to Quantify Chromospheric …

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We study a sample of 21 young and active solar-type stars with spectral types ranging from late F to mid K and characterize the behaviour of their activity. We apply the continuous period search (CPS) time series analysis method on 16 to 27…

Solar and Stellar Astrophysics · Physics 2016-03-21 Jyri Lehtinen , Lauri Jetsu , Thomas Hackman , Perttu Kajatkari , Gregory W. Henry

Studies of absorption spectra of high-z QSOs have revealed that the intergalactic medium at z ~ 2-3 is enriched to ~ 0.1%-1% solar for gas densities more than a few times the mean cosmic density, but have not yet produced an accurate…

Astrophysics · Physics 2016-08-30 Anthony Aguirre , Joop Schaye , Tom Theuns

We report on our observing program to capture simultaneous spectra of Ca II and Balmer lines in a sample of nearby M3 dwarfs. Our goal is to investigate the chromospheric temperature structure required to produce these lines at the observed…

Astrophysics · Physics 2009-11-13 Lucianne M. Walkowicz , Suzanne L. Hawley

If they exist, networks of superconducting cosmic strings are capable of injecting copious amounts of electromagnetic energy into the background over a broad range of frequencies. We study this injection both analytically, as well as…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-18 Bryce Cyr , Jens Chluba , Sandeep Kumar Acharya

The solar analogs of M67 let us glimpse the probable behavior of the Sun on time scales surpassing the duration of human civilization. M67 can serve as a solar proxy because its stars share a similar age and composition with the Sun.…

Solar and Stellar Astrophysics · Physics 2017-06-21 Jason Lee Curtis

We have established and released a new stellar index library of the Ca II Triplet, which serves as an indicator for characterizing the chromospheric activity of stars. The library is based on data from the Large Sky Area Multi-Object Fiber…

Resolving fine details of astronomical objects provides critical insights into their underlying physical processes. This drives in part the desire to construct ever-larger telescopes and interferometer arrays and to observe at shorter…

Combinations of spectroscopic analysis and microscopic techniques are used across many disciplines of scientific research, including material science, chemistry and biology. X-ray spectromicroscopy, in particular, is a powerful tool used…

Medical Physics · Physics 2023-10-17 Oliver Townsend , Silvia Gazzola , Sergey Dolgov , Paul Quinn

Solar simulations and observations show that the detection of long-period Earth-like planets is expected to be very difficult with radial velocity techniques in the solar case because of activity. The inhibition of the convective blueshift…

Solar and Stellar Astrophysics · Physics 2019-07-10 N. Meunier , A. -M. Lagrange , T. Boulet , S. Borgniet

Obtaining measurements of chromospheric and photometric activity of stars with near-solar fundamental parameters and rotation periods is important for a better understanding of solar-stellar connection. We select a sample of 2603 stars with…

A mid-infrared nulling-space interferometer is a promising way to characterize thermal light from habitable planet candidates around Sun-like stars. However, one of the main challenges for achieving this ambitious goal is a high-precision…

Instrumentation and Methods for Astrophysics · Physics 2023-08-04 Taro Matsuo , Felix Dannert , Romain Laugier , Sascha P. Quanz , Andjelka B. Kovacevic , LIFE collaboration

Ground-based surveys such as the Vera C. Rubin Observatory's Legacy Survey of Space and Time require photometric calibration that is both long-term stable and spatially uniform at the sub-per cent level, even during non-photometric…

To address the the problem of calibration of instrument systematics in transit light curves, we present the Python package ExoTiC-ISM. Transit spectroscopy can reveal many different chemical components in exoplanet atmospheres, but such…

Instrumentation and Methods for Astrophysics · Physics 2020-07-16 Iva Laginja , Hannah R. Wakeford

Interstellar reddening corrections are necessary to reconstruct the intrinsic spectral energy distributions (SEDs) of accreting protostellar systems. The stellar SED determines the heating and chemical processes that can occur in…

Astrometric surveys offer us a method to search for elusive cosmic signatures, such as ultralight dark photon dark matter and gravitational waves, by observing the deflection to the apparent positions of the stars. The detection…

High Energy Physics - Phenomenology · Physics 2024-12-03 Haipeng An , Tingyu Li , Jing Shu , Xin Wang , Xiao Xue , Yue Zhao

Interstellar ices play a fundamental role in the physical and chemical evolution of molecular clouds and star-forming regions, yet their large-scale distribution and abundance remain challenging to map. In this work, I present the ice color…

Astrophysics of Galaxies · Physics 2025-10-15 Stefan Meingast

Mapping molecular line emission beyond the bright low-J CO transitions is still challenging in extragalactic studies, even with the latest generation of (sub-)mm interferometers, such as ALMA and NOEMA. We summarise and test a spectral…

Accurately characterizing intrinsic stellar photometric noise induced by stellar astrophysics, such as stellar activity, granulation, and oscillations, is of crucial importance for detecting transiting exoplanets. In this study, we…

Solar and Stellar Astrophysics · Physics 2024-04-23 Jinghua Zhang , Maosheng Xiang , Jie Yu , Jian Ge , Ji-Wei Xie , Hui Zhang , Yaguang Li , You Wu , Chun-Qian Li , Shaolan Bi , Hong-Liang Yan , Jian-Rong Shi

We present near-infrared (0.8-1.8 $\mu$m) spectra of 105 bright (${m_{J}}$ $<$ 10) stars observed with the low resolution spectrometer on the rocket-borne Cosmic Infrared Background Experiment (CIBER). As our observations are performed…

One of the foundations of the Standard Model of Cosmology is statistical isotropy, which can be tested, among other probes, through the study of the Cosmic Microwave Background (CMB). However, a hemispherical power asymmetry on large scales…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-15 C. Gimeno-Amo , R. B. Barreiro , E. Martínez-González , A. Marcos-Caballero
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