Results 21 to 30 of about 909,763 (253)

Correlating Changes in Spot Filling Factors with Stellar Rotation: The Case of LkCa 4

The Astrophysical Journal, 2023
We present a multi-epoch spectroscopic study of LkCa 4, a heavily spotted non-accreting T Tauri star. Using SpeX at NASA’s Infrared Telescope Facility (IRTF), 12 spectra were collected over five consecutive nights, spanning ≈1.5 stellar rotations.
Facundo Pérez Paolino, Jeffrey S. Bary, Michael S. Petersen, Kimberly Ward-Duong, Benjamin M. Tofflemire, Katherine B. Follette, Heidi Mach   +6 more
doaj   +1 more source

Second-Order Gauge-Invariant Cosmological Perturbation Theory: Current Status

Advances in Astronomy, 2010
The current status of the recent developments of the second-order gauge-invariant cosmological perturbation theory is reviewed. To show the essence of this perturbation theory, we concentrate only on the universe filled with a single scalar field ...
Kouji Nakamura
doaj   +1 more source

Exploring the Extremes: Characterizing a New Population of Old and Cold Brown Dwarfs

The Astronomical Journal, 2023
Mapping out the populations of thick disk and halo brown dwarfs is important for understanding the metallicity dependence of low-temperature atmospheres and the substellar mass function.
Aaron M. Meisner, S. K. Leggett, Sarah E. Logsdon, Adam C. Schneider, Pascal Tremblin, Mark Phillips   +5 more
doaj   +1 more source

Unveiling the nature of SN 2022jli: The first double-peaked stripped-envelope supernova showing periodic undulations and dust emission at late times

Astronomy & Astrophysics
We present optical and infrared observations from maximum light until around +800 days of supernova (SN) 2022jli, a peculiar stripped-envelope (SE) SN showing two maxima, each one with a peak luminosity of about 3 × 1042 erg s−1, separated by 50 days ...
Cartier Régis, Contreras Carlos, Stritzinger Maximilian, Hamuy Mario, Ruiz-Lapuente Pilar, Prieto Jose L., Anderson Joseph P., Cikota Aleksandar, Gerlach Matthias   +8 more
doaj   +1 more source

On-board Data Processing to Lower Bandwidth Requirements on an Infrared Astronomy Satellite: Case of Herschel-PACS Camera

EURASIP Journal on Advances in Signal Processing, 2005
This paper presents a new data compression concept, “on-board processing,” for infrared astronomy, where space observatories have limited processing resources.
Christian Reimers, Franz Kerschbaum, Roland Ottensamer, Horst Bischof, Ahmed Nabil Belbachir   +4 more
doaj   +1 more source

DECam Multimessenger Astrophysics Pipeline. I. From Raw Data to Single-exposure Candidates

The Astronomical Journal
We introduce a pipeline that performs rapid image subtraction and source selection to detect transients, with a focus on identifying gravitational-wave optical counterparts using the Dark Energy Camera (DECam). In this work, we present the pipeline steps
Shenming Fu, Thomas Matheson, Aaron Meisner, Yuanyuan Zhang, Sebastián Vicencio, Destry Saul   +5 more
doaj   +1 more source

Cooperative polariton dynamics in feedback-coupled cavities

Nature Communications, 2017
Rabi oscillations of magnons typically do not have few photon control of single spin quantum systems. Here, the authors use a feedback cavity architecture to increase magnon-photon cooperativity, enabling increased control of light-matter interactions in
Bimu Yao, Y. S. Gui, J. W. Rao, S. Kaur, X. S. Chen, W. Lu, Y. Xiao, H. Guo, K. -P. Marzlin, C. -M. Hu   +9 more
doaj   +1 more source

The SPHEREx Target List of Ice Sources (SPLICES)

The Astrophysical Journal, 2023
One of the primary objectives of the SPHEREx mission is to understand the origin of molecules such as H _2 O, CO _2 , and other volatile compounds at the early stages of planetary system formation.
Matthew L. N. Ashby, Joseph L. Hora, Kiran Lakshmipathaiah, Sarita Vig, Rama Krishna Sai Subrahmanyam Gorthi, Miju Kang, Volker Tolls, Gary J. Melnick, Michael W. Werner, Brendan P. Crill, Daniel C. Masters, Carlos Contreras Peña, Jeong-Eun Lee, Jaeyeong Kim, Ho-Gyu Lee, Sung-Yong Yoon, Soung-Chul Yang, Nicholas Flagey, Bertrand Mennesson   +18 more
doaj   +1 more source

Chiral Phonon–Driven Ultrafast Spin Currents in a Non‐Magnetic Ferroelectric

Advanced Materials, EarlyView.
Broadband terahertz emission spectroscopy shows signatures of ultrafast spin‐current generation in non‐magnetic ferroelectric β$\beta$’‐In2Se3${\rm In}_2{\rm Se}_3$. Reversal of the emitted field upon sample inversion and substitution of Pt with W indicates spin‐Hall‐mediated charge conversion, while polarization‐resolved measurements reveal ...
Thomas B. Gill, Ahmet Yagmur, Matthew Rogers, Luke Benson, Nathan Fox, Ben Muggleton, Zabeada Aslam, Conor McCluskey, Phoenix Robinson, Oscar Cespedes, Bryan Hickey, Timothy Moorsom, Marty Gregg, Edmund H. Linfield, Sukhdeep Dhillon, Satoshi Sasaki, Joshua R. Freeman   +16 more
wiley   +1 more source

Infrared fibres in astronomical instrumentation [PDF]

, 1995
For several years multi-object spectroscopy systems have been available for carrying out survey work in the visible region, but until very recently there has not been a system for the near infrared region.
Haynes, Roger
core