Results 71 to 80 of about 37,389 (216)

Revealing the active galactic nucleus in the superantennae through L-band spectroscopy

, 2003
We present an L-band spectrum of the Ultraluminous Infrared Galaxy IRAS 19254-7245 (the Superantennae), obtained with VLT-ISAAC. The high signal to noise ratio allows a study of the main spectral features with unprecedented detail for an extragalactic ...
A. Franceschini, A. Marconi, G. Risaliti, L. Bassani, Laurent O., M. Salvati, Mirabel I. F., Moorwood A. F. M., R. Della Ceca, R. Maiolino, Risaliti G., Roche P. F., S. Berta, V. Braito   +13 more
core   +1 more source

Early evolutionary history of the seed

Biological Reviews, EarlyView.
ABSTRACT The seed is an essential stage in the life history of gymnospermous and angiospermous plants, facilitating both their survival and dispersal. We reappraise knowledge of the evolutionary history of the gymnospermous seed, from its origin in the late Devonian through to the well‐known end‐Permian extinctions – an interval encompassing the ...
Richard M. Bateman, Alan R. T. Spencer, Jason Hilton   +2 more
wiley   +1 more source

Magellan Spectroscopy of Active Galactic Nuclei in Low-mass Galaxies: Scaling Relations and a Triple-peaked Active Galactic Nucleus

The Astrophysical Journal
In this work, we aim to further populate the low-mass regime of black hole (BH) scaling relations to better understand the formation and growth mechanisms of central supermassive BHs. We target six galaxies that have been previously identified as hosting
Megan R. Sturm, Amy E. Reines, Jenny Greene, Sheyda Salehirad   +3 more
doaj   +1 more source

Optical quasi-periodic oscillations of the quasar 4C 50.43 with different periodicities in CSS and ZTF light curves

Astronomy & Astrophysics
Long-standing optical quasi-periodic oscillations (QPOs) with periodicities of hundreds to thousands of days have been accepted as indicators of central sub-parsec binary black hole systems in broad line active galactic nuclei (BLAGNs).
Liao GuiLin, Chen XingQian, Cheng PeiZhen, Zhang Xue-Guang   +3 more
doaj   +1 more source

X-Ray Flares in the Long-term Light Curve of Low-luminosity Active Galactic Nucleus M81*

The Astrophysical Journal, 2023
Most active galactic nuclei at the center of the nearby galaxies have supermassive black holes accreting at sub-Eddington rates through hot accretion flows or radiatively inefficient accretion flows, which efficiently produce jets.
Gunjan Tomar, Nayantara Gupta
doaj   +1 more source

QPO in RE J1034+396: model constraints from observed trends

, 2012
We analyze the time variability of the X-ray emission of RE J1034+396, an active galactic nucleus with the first firm detection of a quasi-periodic oscillations (QPO).
Czerny, B., Das, Tapas K., Dovciak, M., Karas, V., Lachowicz, P., Pechacek, T.   +5 more
core   +1 more source

High-energy monitoring of Seyfert galaxies: the case of NGC 4593 [PDF]

, 2015
We discuss preliminary results from a joint XMM-Newton and NuSTAR monitoring program on the active galactic nucleus NGC 4593, consisting of 5x20 ks observations, spaced by two days, performed in January 2015.
Arav, Ballantyne, Baloković, Bianchi, Boissay, Brenneman, Brenneman, Denney, Di Gesu, Done, Grupe, Guainazzi, Haardt, Haardt, Haardt, Harrison, Jansen, Kaastra, Kaastra, Malizia, Marinucci, Markowitz, Mehdipour, Perola, Petrucci, Piconcelli, Reynolds, Sobolewska, Soldi, Strauss, Ursini, Walton   +31 more
core   +4 more sources

Probing the Heart of an Active Galactic Nucleus: NGC 1068 [PDF]

Symposium - International Astronomical Union, 2001
We present results from integral field spectroscopy of the narrow line region of NGC 1068, carried out with the MPE 3D near infrared imaging spectrometer. A map and velocity field of the [Fe II] fine structure line at 1.64μm is presented. The kinematics of the [Fe II] emission, which arises in partially ionized zones, shows red shifted emission in the ...
Tecza, M, Thatte, N, Maiolino, R
openaire   +2 more sources

Talin1 Adhesion Morphology and Colocalization With Tensin3 Are Largely Unaffected by Polyacrylamide Substrate Stiffness

Cytoskeleton, EarlyView.
ABSTRACT Cells sense the stiffness of their extracellular matrix (ECM) and adapt their behavior accordingly. We investigated how ECM stiffness affects the spatial organization of talin1, a key mechanosensitive focal adhesion protein. Using polyacrylamide (PA) hydrogels with tunable stiffnesses (0.2–188 kPa), we analyzed cell morphology, migration ...
Joanna Hajduk, Patrycja Twardawa, Sylwia Bobis‐Wozowicz, Marta Szewczyk, Zenon Rajfur, Zbigniew Baster   +5 more
wiley   +1 more source

The major merger–active galactic nucleus connection up to cosmic noon

Astronomy & Astrophysics
Galaxy major mergers are a potential mechanism for triggering active galactic nuclei (AGN) activity, but their role remains debated, particularly beyond the local Universe.
La Marca A., Margalef-Bentabol B., Wang L., Trager S. C., Rodriguez-Gomez V., Martin G.   +5 more
doaj   +1 more source