A5053089718- Astrophysics and Star Formation Studies
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Agriculture, Soil, Plant Science
- Astrophysical Phenomena and Observations
- Astronomy and Astrophysical Research
- Scientific Computing and Data Management
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Atmospheric and Environmental Gas Dynamics
- Smart Agriculture and AI
- Irrigation Practices and Water Management
- Soil Geostatistics and Mapping
- Atmospheric Ozone and Climate
- Astro and Planetary Science
- Chemistry and Stereochemistry Studies
- Optical Systems and Laser Technology
- Rice Cultivation and Yield Improvement
- Diverse Scientific and Economic Studies
- Planetary Science and Exploration
- Astrophysics and Cosmic Phenomena
- Metabolomics and Mass Spectrometry Studies
- Advanced Software Engineering Methodologies
- Model-Driven Software Engineering Techniques
- Coagulation, Bradykinin, Polyphosphates, and Angioedema
Arizona State University
2022-2023
Kingston Hospital
2022
Northumbria University
2022
National Socio-Environmental Synthesis Center
2020-2022
University of Vermont
2019-2020
Gemini North Observatory
2007-2019
Gemini South Observatory
2007-2015
NIU Observatory
2007-2015
University of Roehampton
2005-2014
Capgemini (Netherlands)
2013
We used the CLUMPY torus models and a Bayesian approach to fit infrared spectral energy distributions ground-based high angular resolution mid-infrared spectroscopy of 13 nearby Seyfert galaxies. This allowed us put tight constraints on model parameters such as viewing angle i, radial thickness Y, size cloud distribution σtorus, average number clouds along equatorial rays N0. found that i is not only parameter controlling classification galaxy into type 1 or 2. In principle, 2s could be...
We present new mid-infrared imaging data for three Type-1 Seyfert galaxies obtained with T-ReCS on the Gemini-South Telescope at subarcsecond resolution. Our aim is to enlarge sample studied in a previous work compare properties of and Type-2 tori using clumpy torus models Bayesian approach fit infrared (IR) nuclear spectral energy distributions. Thus, considered here comprises 7 Type-1, 11 Type-2, 3 intermediate-type Seyferts. The unresolved IR emission 1 can be reproduced by combination...
Recent theoretical and observational works indicate the presence of a correlation between star formation rate (SFR) active galactic nuclei (AGN) luminosity (and, therefore, black hole accretion rate) Seyfert galaxies. This suggests physical connection gas forming stars on kpc scales sub-pc that is feeding hole. We compiled largest sample galaxies to date with high angular resolution (0.4-0.8 arcsec) mid-infrared (8-13 micron) spectroscopy. The includes 29 drawn from AGN Revised Shapley-Ames...
We present spatially-resolved, near-diffraction-limited 10 micron spectra of the nucleus Seyfert 2 galaxy NGC 1068, obtained with Michelle, mid-IR imager and spectrometer on 8.1 m Gemini North telescope. The cover central 6.0" x 0.4" ionization cones at a spatial resolution approximately (approx. 30 parsecs). extracted in steps along slit reveal striking variations continuum slope, silicate feature profile depth, fine structure line fluxes subarcsecond scales, illustrating unprecedented...
We present Gran Telescopio CANARIAS CanariCam 8.7 μm imaging and 7.5–13 spectroscopy of six local systems known to host an active galactic nucleus (AGN) have nuclear star formation. Our main goal is investigate whether the molecules responsible for 11.3 polycyclic aromatic hydrocarbon (PAH) feature are destroyed in close vicinity AGN. detect PAH emission regions galaxies as well extended over a few hundred parsecs. The equivalent width (EW) shows minimum at but increases with increasing...
We present results from the fitting of infrared (IR) spectral energy distributions 21 active galactic nuclei (AGNs) with clumpy torus models. compiled high spatial resolution (∼0.3–0.7 arcsec) mid-IR (MIR) N-band spectroscopy, Q-band imaging, and nuclear near- MIR photometry literature. Combining these observations, far-IR photometry, models enables us to put constraints on properties geometry. divide sample into three types according broad line region (BLR) properties: type-1s, type-2s...
We present near-infrared (NIR) time-series spectroscopy, as well complementary ultraviolet (UV), optical, and NIR data, of the Type Ia supernova (SN Ia) iPTF13ebh, which was discovered within two days from estimated time explosion. The first spectrum taken merely 2.3 after explosion may be earliest yet obtained a SN Ia. most striking features in are several C I lines, λ1.0693 μm line is strongest ever observed Interestingly, no strong optical II counterparts were found, even though...
Context. The unified model of active galactic nuclei (AGN) claims that the properties AGN depend on viewing angle observer with respect to a toroidal distribution dust surrounding nucleus. Both mid-infrared (MIR) attenuation and continuum luminosity are expected be related associated torus. Therefore, isolating nuclear component is essential for studying MIR emission AGN.
Applying prototype-oriented development processes to computerized application systems significantly improves the likelihood that useful will be developed and overall cycle shortened. The prototype methodology tool presented here have been widely applied of interactive information in commercial data processing setting. effectiveness relationship other applications is discussed.
We present high-resolution mid-infrared (MIR) imaging, nuclear spectral energy distributions (SEDs), and archival Spitzer spectra for 22 low-luminosity active galactic nuclei (LLAGNs; Lbol ≲ 1042 erg s−1). Infrared (IR) observations may advance our understanding of the accretion flows in LLAGNs, fate obscuring torus at low rates, and, perhaps, star formation histories these objects. However, while comprehensively studied higher-luminosity Seyferts quasars, IR properties LLAGNs have not yet...
Understanding the origin and diversity of emission processes responsible for Gamma-ray Bursts (GRBs) remains a pressing challenge. While prompt contemporaneous panchromatic observations have potential to test predictions internal-external shock model, extensive multiband imaging has been conducted only few GRBs. We present rich, early-time, datasets two \swift\ events, GRB 110205A 110213A. The former shows optical since early stages phase, followed by steep rising in flux up ~1000s after...
We present an atlas of mid-infrared (mid-IR) ~7.5-13micron spectra 45 local active galactic nuclei (AGN) obtained with CanariCam on the 10.4m Gran Telescopio CANARIAS (GTC) as part ESO/GTC large program. The sample includes Seyferts and other low luminosity AGN (LLAGN) at a median distance 35Mpc luminous AGN, namely PG quasars, (U)LIRGs, radio galaxies (RG) 254Mpc. To date, this is largest mid-IR spectroscopic catalog sub-arcsecond resolution (median 0.3arcsec). goal work to give overview...
Aliphatic hydrocarbons exhibit an absorption feature at 3.4 μm, observed toward sources that sample diffuse regions of the interstellar medium (ISM). The absorbers responsible for this are assumed to reside in some component dust, but physical nature particles (size, shape, structure, etc.) is uncertain. Observations polarization provide discrimination. Since grains carry silicate known be aligned, across μm hydrocarbon can used test silicate-core organic refractory mantle grain theory....
Dust reprocesses the intrinsic radiation of active galactic nuclei (AGNs) to emerge at longer wavelengths. The observed mid-infrared (MIR) luminosity depends fundamentally on central engine, but in detail it also geometric distribution surrounding dust. To quantify this relationship, we observe nearby normal AGNs MIR achieve spatial resolution better than 100 pc, and use absorption-corrected X-ray as a proxy for AGN emission. We find no significant difference between optically classified...
The unified model of active galactic nuclei (AGNs) predicts silicate emission features at 10 and 18 μm in type 1 AGNs, such have now been observed objects ranging from distant quasi-stellar to nearby LINERs. More surprising, however, is the detection a few 2 AGNs. By combining Gemini Spitzer mid-infrared imaging spectroscopy NGC 2110, closest known Seyfert galaxy with features, we can constrain location silicate-emitting region within 32 pc nucleus. This strongest constraint yet on size any...
It has been widely argued that agroecological science, which originally developed as the application of ecological principles to agricultural systems, should engage with social and political issues affect production agriculture, incorporate knowledge from a variety sources. In this paper, we use techniques network science bibliometrics evaluate degree transformation taken place. By creating networks based on over 3,000 agroecology papers roughly 160,000 references they cite, distinguish...
We discuss Subaru and Spitzer Space Telescope imaging spectroscopy of M87 in the mid-infrared (mid-IR) from 5 to 35 μm. These observations allow us investigate mid-IR emission mechanisms core establish that flaring, variable jet component HST-1 is not a major contributor flux. The data include high signal-to-noise ratio 15-35 μm spectrum knot A/B complex jet, which consistent with synchrotron emission. However, model cannot account for observed nuclear spectrum, even when contributions...
We present high spatial resolution mid-IR images of the nuclear region NGC 5128 (Centaurus A). Images were obtained at 8.8 μm, N band (10.4 μm), and 18.3 μm using imager/spectrometer T-ReCS on Gemini South. These show a bright unresolved core surrounded by low-level extended emission. place an upper limit to size nucleus 3.2 pc (0.19'') 3.5 (0.21'') level FWHM. The most likely source emission is from dusty torus possibly narrow-line with some contribution synchrotron associated jet as well...
This paper presents spectra in the 2 to 20 μm range of quiescent cloud material located IC 5146 complex. The were obtained with NASA's Infrared Telescope Facility SpeX instrument and Spitzer Space Telescope's Spectrometer. We use these investigate dust ice absorption features pristine regions that are unaltered by embedded stars. find H2O-ice threshold extinction is 4.03 ± 0.05 mag. Once foreground taken into account, however, drops 3.2 mag, equivalent found for Taurus dark cloud, generally...
We present spectra of the nuclear regions 50 nearby (D = 1–92 Mpc, median 20 Mpc) galaxies morphological types E to Sm. The spectra, obtained with Gemini Near-IR Spectrograph on North telescope, cover a wavelength range approximately 0.85–2.5 μm at R ∼ 1300–1800. There is evidence that most host an active galactic nucleus (AGN), but AGN luminosities (log (L [erg s−1]) 37.0–43.2) in sample means display wide variety features. Some nuclei, especially Seyferts, exhibit rich emission-line...