A5052524031- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Astrophysical Phenomena and Observations
- Scientific Research and Discoveries
- Spectroscopy and Laser Applications
- Gamma-ray bursts and supernovae
- Molecular Spectroscopy and Structure
- Leaf Properties and Growth Measurement
- Geometric Analysis and Curvature Flows
- Advanced Chemical Physics Studies
- Phase Equilibria and Thermodynamics
- Remote Sensing in Agriculture
- Advanced Differential Geometry Research
- Plant Water Relations and Carbon Dynamics
- Astro and Planetary Science
- History and Developments in Astronomy
- Intellectual Property and Patents
- Advanced Measurement and Metrology Techniques
- Seismic Imaging and Inversion Techniques
- Carbohydrate Chemistry and Synthesis
- Geophysics and Gravity Measurements
- Language, Metaphor, and Cognition
University of Mohaghegh Ardabili
2018
AlbaNova
2007-2016
Stockholm University
2007-2016
Trinity House
2013
Instituto de Astrofísica de Canarias
2006-2012
Rochester Institute of Technology
2005-2011
Astronomical Observatory
2007-2008
University of Groningen
2006
University of Nottingham
2003-2004
Observatoire de Lyon
2003-2004
We present the emission-line fluxes and kinematics of 48 representative elliptical lenticular galaxies obtained with our custom-built integral-field spectrograph SAURON. Hb, [OIII], [NI] emission lines were measured using a new procedure that simultaneously fits both stellar spectrum lines. Using this technique we can detect down to an equivalent width 0.1A set by current limitations in describing galaxy spectra synthetic real templates, rather than quality spectra. Emission is detected 75%...
We present observations of the stellar and gas kinematics for a representative sample 24 Sa galaxies obtained with our custom-built integral-field spectrograph SAURON operating on William Herschel Telescope. The data have been homogeneously reduced analysed by means dedicated pipeline. All resulting cubes were spatially binned to minimum mean signal-to-noise ratio 60 per spatial spectral resolution element. Our maps typically cover bulge-dominated region. find significant fraction...
We discuss the selection and observations of a large sample nearby galaxies, which we are using to quantify star formation activity in local Universe. The consists 334 galaxies across all Hubble types from S0/a Im with recession velocities between 0 3000 km s-1. basic data for each galaxy narrow band H[Nii] R-band imaging, derive rates, equivalent widths surface brightnesses, total magnitudes. A strong correlation is found rate type, strongest isolated occurring Sc Sbc types. More...
We have used GMOS-IFU and high-resolution HST-ACS observations to map, in unprecedented detail, the gas velocity field structure within 0.7 kpc circumnuclear ring of SBb LINER/Seyfert 1 galaxy NGC 1097. find clear evidence radial streaming motions associated with spiral structures leading unresolved (<3.5 pc) nucleus, which we interpret as part fueling chain by is transported nuclear starburst supermassive black hole.
Abstract We present the first 100 pc scale view of dense molecular gas in central ∼1.3 kpc type-1 Seyfert NGC 1097, traced by HCN (J = 4–3) and HCO+ lines afforded with ALMA band 7. This galaxy shows significant enhancement respect to CO low-J transitions, which seems be a common characteristic AGN environments. Using data, we consider characteristics around this AGN, search for mechanism enhancement. find high line ratio nucleus. The upper limit brightness temperature (v 2 11f , J is 0.08,...
ABSTRACT Compiling data from literature and the Atacama Large Millimeter/submillimeter Array archive, we show enhanced HCN(4–3)/HCO + (4–3) and/or HCN(4–3)/CS(7–6) integrated intensity ratios in circumnuclear molecular gas around active galactic nuclei (AGNs) compared to those starburst (SB) galaxies (submillimeter HCN enhancement). The number of sample is significantly increased our previous work. We expect that this feature could potentially be an extinction-free energy diagnostic tool...
The nearby Sy 1 galaxy NGC 1097 represents an ideal laboratory to explore the molecular chemistry in presence and surroundings of active galactic nucleus. Exploring distribution different species allows us understand physical processes affecting ISM both AGN vicinity as well outer star forming ring. We carried out 3 mm ALMA observations HCN, HCO+, CCH, CS, HNCO, SiO, HC3N, SO 13C isotopologues. All were imaged over central 2 kpc (~30") at a resolution ~2.2"x1.5 (150 pc x 100 pc). HCO+ CS...
We report the discovery of gas streaming motions along nuclear spiral arms toward LINER nucleus galaxy NGC 6951. The observations, obtained using GMOS integral field spectrograph on Gemini North telescope, yielded maps flux distributions and kinematics in Hα, [N II] λ6584, [S λλ6717, 6731 emission lines inner 7'' × 15'' galaxy. This region includes a circumnuclear star-forming ring with radius ~500 pc, inside ring, nucleus. ionized is dominated by rotation, but subtraction kinematic model...
(Abridged) We present densely sampled BVRI light curves of the optical transient associated with gamma-ray burst GRB 030329, result a coordinated observing campaign conducted at five observatories. Augmented published observations this GRB, compiled dataset contains 2687 photometric measurements, obtained between 78 minutes and 79 days after burst. show that underlying supernova 2003dh evolved faster than, was probably somewhat fainter than type Ic SN 1998bw, 980425. find our data can be...
We present Sauron 2D spectrography of the central 1.5 kpc nearby Sey2 galaxy NGC1068, encompassing well-known NIR inner bar. have successively disentangled respective contributions ionized gas and stars, thus deriving their distribution kinematics. The [OIII] Hbeta emission lines exhibit very different spatial kinematics, latter following spiral arms with clumps associated star formation. Strong inwards streaming motions are observed in both stellar kinematics also clear signatures a...
This is the second part of an Hα kinematics follow-up survey Spitzer Infrared Nearby Galaxies Survey (SINGS) sample. The aim this paper to shed new light on role baryons and their dark/luminous matter relation in star-forming regions galaxies, with studies at other wavelengths. data for 37 galaxies are presented. observations were made using Fabry–Perot interferometry photon-counting camera FaNTOmM four different telescopes, namely Canada–France–Hawaii 3.6-m, ESO La Silla William Herschel...
We have applied the Tremaine–Weinberg method to 10 late-type barred spiral galaxies using data cubes, in Hα emission, from FaNTOmM and GHαFaS Fabry–Perot spectrometers. combined derived bar (and/or spiral) pattern speeds with angular frequency plots measure corotation radii for bars these galaxies. base our results on a combination of this morphological analysis designed estimate radius bar-length ratio two independent techniques archival near-infrared images, although we are aware...
We present a harmonic expansion of the observed line-of-sight velocity field as method to recover and investigate spiral structures in nuclear regions galaxies. apply it emission-line within circumnuclear star-forming ring NGC 1097, obtained with GMOS-IFU spectrograph. The radial variation third terms is well described by logarithmic spiral, from which we interpret that gravitational potential weakly perturbed two-arm density wave an inferred pitch angle 52° ± 4°. This interpretation...
We explore the role that gravitational instability plays in NGC 1068, a nearby Seyfert galaxy exhibits unusually vigorous starburst activity. For this purpose, we use Romeo–Falstad disc diagnostics and data from BIMA Survey of Nearby Galaxies, Sloan Digital Sky Spectrographic Areal Unit for Research on Optical Nebulae. Our analysis illustrates 1068 is gravitationally unstable 'monster'. Its subject to powerful instabilities. Several processes, including feedback active galactic nucleus...
We present Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 1 observations of the central kiloparsec region luminous type Seyfert galaxy NGC 7469 with unprecedented high resolution (05 ×04 = 165 × 132 pc) at submillimeter wavelengths. Utilizing wide bandwidth ALMA, we simultaneously obtained HCN(4–3), HCO+(4–3), CS(7–6), and partially CO(3–2) line maps, as well 860 μm continuum. The consists ∼1'' component surrounding starburst ring a radius ∼15–25. Several structures connect these...
We present SAURON integral-field observations of the S0 galaxy NGC7332. Existing broad-band ground-based and HST photometry reveals a double disk structure boxy bulge interpreted as bar viewed close to edge-on. The two-dimensional stellar kinematic maps confirm existence inner but also uncover presence cold counter-rotating component within central 250 pc. Hbeta [OIII] emission line show that ionised gas has complex morphology kinematics, including both with respect stars fainter co-rotating...
We have derived disk scale lengths for 30374 non-interacting galaxies in all five SDSS bands. Virtual Observatory methods and tools were used to define, retrieve, analyse the images this unprecedentedly large sample classified as disk/spiral LEDA catalogue. Cross correlation of with catalogue allowed us investigate variation different types galaxies. further investigat asymmetry, concentration, central velocity dispersion indicators morphological type, are able assess how length varies...
(abridged) Luminous blue compact galaxies are among the most active in local universe terms of their star formation rate per unit mass. They may be seen as analogs higher redshift Lyman Break Galaxies. Studies kinematics is key to understanding what triggers unusually In this work we investigate stars and ionised gas Haro11, one luminous universe. Previous works have indicated that many such triggered by galaxy mergers. We employed Fabry-Perot interferometry, long-slit spectroscopy Integral...
We analyse SAURON kinematic maps of the inner kpc early-type (Sa) barred spiral galaxy NGC5448. The observed morphology and kinematics emission-line gas is patchy perturbed, indicating clear departures from circular motion. stars more regular, display a small disk-like system embedded in large-scale rotating structure. focus on [OIII] gas, use harmonic decomposition formalism to velocity field. higher-order terms main features data are consistent with an analytically constructed simple bar...
Aims.We study two dimensional Fabry-Perot interferometric observations of the nearby face-on late-type spiral galaxy, NGC 628, in order to analyse ionized gas component interstellar medium. Covering galaxy out a radius larger than 12 kpc, and with spatial sampling 16, we aim investigate large-scale dynamics as well feedback from individual H ii regions into their surrounding
In this Letter, we introduce a technique for finding resonance radii in disk galaxy. We use two-dimensional velocity field Hα emission obtained with Fabry–Perot interferometry, derive the classical rotation curve, and subtract it off, leaving residual map. As streaming motions should reverse sign at corotation, detect these reversals plot them histogram against galactocentric radius, excluding points where amplitude of reversal is smaller than measurement uncertainty. The histograms show...
We present a kinematic analysis of the dense molecular gas in central 200 pc nearby galaxy NGC 1097, based on Cycle 0 observations with Atacama Large Millimeter/submillimeter Array (ALMA). use HCN(4–3) line to trace densest interstellar ( cm−3), and quantify its kinematics, estimate an inflow rate for gas. find striking similarity between ALMA data analytic spiral model that we have previously constructed ionized velocity fields larger scales. are able follow streaming down 40 distance from...