A5081902887- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astrophysics and Cosmic Phenomena
- Quantum Information and Cryptography
- Quantum Computing Algorithms and Architecture
- Adaptive optics and wavefront sensing
- Quantum optics and atomic interactions
- Quantum Mechanics and Applications
- Solar and Space Plasma Dynamics
- Space Exploration and Technology
- History and Developments in Astronomy
- Spectroscopy and Chemometric Analyses
- Pulsars and Gravitational Waves Research
- Radio Astronomy Observations and Technology
- Quantum and electron transport phenomena
- Music Technology and Sound Studies
- Atmospheric Ozone and Climate
- Advanced Semiconductor Detectors and Materials
- CCD and CMOS Imaging Sensors
European Space Research and Technology Centre
2023
Gemini North Observatory
2008-2022
Johannes Gutenberg University Mainz
2013-2022
Gemini South Observatory
2005-2020
NIU Observatory
2008-2020
Kitt Peak National Observatory
2014
Optica
2014
McMaster University
2013
Folkwang University of the Arts
2013
University of Siegen
2013
The globular cluster omega Centauri is one of the largest and most massive members galactic system. However, its classification as a has been challenged making it candidate for being stripped core an accreted dwarf galaxy; this together with fact that velocity dispersions star clusters in our galaxy makes interesting harboring intermediate mass black hole. We measure surface brightness profile from integrated light on HST}/ACS image center, find central power-law cusp logarithmic slope...
Since the first report of a potentially non-solar carbon-to-oxygen ratio (C/O) in its dayside atmosphere, highly irradiated exoplanet WASP-12b has been under intense scrutiny and subject many follow-up observations. Additionally, recent discovery stellar binary companions ~1" from WASP-12 obfuscated interpretation observational data. Here we present new ground-based multi-object transmission-spectroscopy observations that acquired over two consecutive nights red optical with Gemini-N/GMOS....
We report the discovery of an extensive system scattered-light echo arclets associated with recent supernovae in local neighborhood Milky Way: Tycho (SN 1572) and Cassiopeia A. Existing work suggests that SN was a thermonuclear explosion while Cas A supernova core-collapse explosion. Precise classifications according to modern nomenclature require spectra outburst light. In case ancient SNe, this can only be done spectroscopy their light echo, where echoes from is first step. Adjacent...
We report the successful identification of type supernova responsible for remnant SNR 0509-675 in Large Magellanic Cloud (LMC) using Gemini spectra surrounding light echoes. The ability to classify outbursts associated with centuries-old remnants provides a new window into several aspects research and is likely be providing constraints on additional LMC supernovae as well their historical counterparts Milky Way Galaxy (MWG). combined spectrum echo from shows broad emission absorption lines...
Dicke states are a family of multi-qubit quantum with interesting entanglement properties and they have been observed in many experiments. We construct witnesses for detecting genuine multiparticle the vicinity these states. use approach positive partial transpose mixtures to derive conditions analytically. For nearly all cases, our criteria stronger than previously known.
We propose a projection measurement onto encoded Bell states with static network of linear optical elements. By increasing the size quantum error correction code, both efficiency and photon-loss tolerance can be made arbitrarily high at same time. As main application, we show that all-optical communication over large distances rates similar to those classical is possible solely based on local state teleportations using sources states, fixed arrays beam splitters, photon detectors. another...
The so-called NOON states are quantum optical resources known to be useful especially for lithography and metrology. At the same time, they very sensitive photon losses rather hard produce experimentally. Concerning former, here we present a scheme where elementary building error-correction codes against losses, thus demonstrating that such can also suppress effect of loss. Our code is an exact systematically extended from one-photon higher-number losses. Its loss scaling depending on...
We present the complete optical transmission spectrum of hot Jupiter WASP-4b from 440-940 nm at R ~ 400-1500 obtained with Gemini Multi-Object Spectrometers (GMOS); this is first result a comparative exoplanetology survey program close-in gas giants conducted GMOS. has an equilibrium temperature 1700 K and favorable to study in due large scale height (370 km). derive using 4 transits observed MOS technique. demonstrate repeatable results across multiple epochs GMOS, combined precision about...
We analyse a generalised quantum error correction code against photon loss where logical qubit is encoded into subspace of single oscillator mode that spanned by distinct multi-component cat states (coherent-state superpositions). present systematic construction includes the extension an existing one-photon-loss to higher numbers losses. When subject (amplitude damping) channel, qubits are shown exhibit cyclic behaviour and spaces each correspond certain multiples losses, half which can be...
We report the first detection of asymmetry in a supernova (SN) photosphere based on SN light echo (LE) spectra Cas A from different perspectives dust concentrations its LE ellipsoid. New LEs are reported difference images, and optical these analyzed compared. After properly accounting for effects finite dust-filament extent inclination, we find one field where He I H alpha features blueshifted by an additional ~4000 km/s relative to other Type IIb 1993J. That same direction does not show any...
The solar corona maintains temperatures of a million Kelvin or more. plasma heating mechanisms responsible for these extreme are still unclear. Large regions magnetic activity in the photosphere cause ultraviolet (EUV) emission corona. Even smaller with bipolar and multipolar fields can generate coronal bright points (CBPs). We performed statistical analysis 346 CBPs. used Solar Dynamics Observatory (SDO) images to track CBPs on continuous basis. Therefore, we were able collect database...
We present a study of the stellar populations galaxies in cluster RX J0152.7-1357 at redshift 0.83. The is based on new high signal-to-noise ratio spectroscopy 29 members covering wavelength range 5000–10000 Å, as well r'i'z' photometry cluster. use scaling relations between central velocity dispersions and their luminosities, Balmer line strengths, various metal strengths to parameterize differences our low-redshift comparison sample. luminosities higher order lines Hγ Hδ (for...
The Gemini Near Infrared Spectrograph on South unlocks new possibilities to study the central black holes (BHs) in dusty galaxies that have been inaccessible previous BH studies. We exploit good near-infrared seeing measure of Centaurus A (NGC 5128). stellar kinematics NGC 5128 using region around CO band heads at 2.3 μm and determine mass axisymmetric orbit-based models. BHs are believed be essential components galaxies, their evolutionary states appear closely linked those hosts. Our...
In this work we present the first results of a study BAL QSOs (at low and high redshift), based on very deep Gemini GMOS integral field spectroscopy. particular, obtained for nearest IR QSO Mrk 231 are presented. Very three-dimensional spectra maps clearly show that systems I II extended (reaching 1.4-1.6" = 1.2-1.3 kpc, from nucleus) elongated at position angle close to radio jet PA. Which suggest both associated with jet, supporting bipolar jet-wind model some BALs. For nuclear region 231,...
We present the fundamental plane (FP) for 38 early-type galaxies in two rich galaxy clusters RX J0152.7-1357 (z = 0.83) and J1226.9+3332 0.89), reaching a limiting magnitude of MB -19.8 rest frame clusters. While zero-point offset FP these high-redshift relative to our low-redshift sample is consistent with passive evolution formation redshift zform ≈ 3.2, not only shifted as expected mass-independent but rotated sample. Expressed relation between masses mass-to-light ratios, significantly...
We have discovered strong gravitational lensing features in the core of nearby cluster Abell 3827 by analyzing Gemini South GMOS images. The most prominent feature is a highly-magnified, ring-shaped configuration four images around central cD galaxy. spectroscopic analysis puts this source at z~0.2. Located ~20" away from galaxy secondary tangential arc which has been identified as background with z~0.4. modeled potential core, taking into account mass cluster, BCG and other galaxies. derive...
RXJ0848.6+4453 (Lynx W) at redshift 1.27 is part of the Lynx Supercluster galaxies. Our analysis stellar populations and star formation history in cluster covers 24 members based on deep optical spectroscopy from Gemini North imaging data HST. Focusing 13 bulge-dominated galaxies for which we can determine central velocity dispersions, find that these show a smaller evolution sizes dispersions than reported field poorer clusters. The populate Fundamental Plane similar to found lower clusters...
We present the first results of a narrow-band photometric study massive galaxy cluster XMMU J2235.3−2557 at z= 1.39. obtained deep H imaging with Near InfraRed Imager and Spectrometer on Gemini North, corresponding to Hα emission cluster's redshift. Our sample consists 82 galaxies within radius ∼500 kpc, 10 which are spectroscopically confirmed members. 16 identified as excess line-emitters. Among just line-emitting galaxies, we find an average star formation rate (SFR) 3.6 ± 1.3 M⊙ yr−1....
We have used deep integral field spectroscopy obtained with the GMOS instrument on Gemini-North to determine spatial distribution of post-starburst stellar population in four luminous E+A galaxies at z<0.04. find all centrally-concentrated gradients young contained within central ~1 kpc. This is agreement Balmer line found local low luminosity galaxies. The results from higher redshift (z~0.1) samples been varied, but general signature be extended or a galaxy-wide phenomenon otherwise failed...
We propose an experimental scheme to generate, in a heralded fashion, arbitrary quantum superpositions of two-mode optical states with fixed total photon number $n$ based on weakly squeezed state resources (obtained via weak parametric down conversion), linear optics, and detection. Arbitrary $d$-level (qudit) can be created this way where $d=n+1$. Furthermore, we experimentally demonstrate our for $n=2$. The resulting qutrit are characterized homodyne tomography. also discuss possible...
We present a hybrid quantum repeater protocol for the long-distance distribution of atomic entangled states beyond qubits. In our scheme, imperfect noisy pairs two qudits, i.e., discrete-variable $d$-level systems, each of, in principle, arbitrary dimension $d$, are initially shared between intermediate stations channel. This is achieved via local, sufficiently strong light-matter interactions, involving optical coherent and their transmission after these measurements on transmitted field...
We present a study of outflow (OF) and broad absorption line (BAL) systems in Mrk 231, similar infrared (IR) quasi-stellar objects (QSOs). This is based mainly on one-dimensional two-dimensional spectroscopy (obtained at La Palma/William Herschel Telescope, Hubble Space International Ultraviolet Explorer, European Southern Observatory/New Technology Kitt Peak National Observatory, Apache Point Observatory Complejo Astronomico El Leoncito observatories) plus Telescope images. For we report...
We report direct evidence for asymmetry in the early phases of SN 1987A via optical spectroscopy five fields its light echo system. The echoes allow first few hundred days explosion to be reobserved, with different position angles providing viewing supernova. Light therefore allows a spectroscopic comparison originating from regions photosphere during 1987A. Gemini multi-object shows fine-structure H-alpha line as smooth function angle on near-circular rings. profiles northern hemisphere...
Time-series spectrophotometric studies of exoplanets during transit using ground-based facilities are a promising approach to characterize their atmospheric compositions. We aim investigate the spectrum hot Jupiter HAT-P-1b. compare our results those obtained at similar wavelengths by previous space-based observations. observed two transits HAT-P-1b with Gemini Multi-Object Spectrograph (GMOS) instrument on North telescope modes covering 320 - 800 nm and 520 950 wavelength ranges. used...