Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Institution
- Publication
- Publication Type
Articles 1 - 7 of 7
Full-Text Articles in Physics
A Deep Look At The Nuclear Region Of Ugc 5101 Through High Angular Resolution Mid-Ir Data With Gtc/Canaricam, M. Martínez-Paredes, Almudena Alonso-Herrero, Itziar Aretxaga, C. Ramos Almeida, A. Hernán-Caballero, O. González-Martín, M. Pereira-Santaella, Christopher Packham, A. Asensio Ramos, T. Díaz-Santos, Moshe Elitzur, P. Esquej, I. García-Bernete, Masatoshi Imanishi, Nancy A. Levenson, José Miguel Rodríguez Espinosa
A Deep Look At The Nuclear Region Of Ugc 5101 Through High Angular Resolution Mid-Ir Data With Gtc/Canaricam, M. Martínez-Paredes, Almudena Alonso-Herrero, Itziar Aretxaga, C. Ramos Almeida, A. Hernán-Caballero, O. González-Martín, M. Pereira-Santaella, Christopher Packham, A. Asensio Ramos, T. Díaz-Santos, Moshe Elitzur, P. Esquej, I. García-Bernete, Masatoshi Imanishi, Nancy A. Levenson, José Miguel Rodríguez Espinosa
Physics and Astronomy Faculty Publications
We present an analysis of the nuclear infrared (IR, 1.6–18 μm) emission of the ultraluminous IR galaxy UGC 5101 to derive the properties of its active galactic nucleus (AGN) and its obscuring material. We use new mid-IR high angular resolution (0.3–0.5 arcsec) imaging using the Si-2 filter (λC = 8.7 μm) and 7.5–13 μm spectroscopy taken with CanariCam (CC) on the 10.4 m Gran Telescopio CANARIAS. We also use archival Hubble Space Telescope/NICMOS and Subaru/COMICS imaging and Spitzer/IRS spectroscopy. We estimate the near- and mid-IR unresolved nuclear emission by modelling the imaging data with GALFIT. We decompose …
Herschel Dust Emission As A Probe Of Starless Cores Mass: Mcld 123.5+24.9 Of The Polaris Flare, Gururaj Anil Wagle, Thomas H. Troland, Gary J. Ferland, Nicholas P. Abel
Herschel Dust Emission As A Probe Of Starless Cores Mass: Mcld 123.5+24.9 Of The Polaris Flare, Gururaj Anil Wagle, Thomas H. Troland, Gary J. Ferland, Nicholas P. Abel
Physics and Astronomy Faculty Publications
We present newly processed archival Herschel images of molecular cloud MCLD 123.5+24.9 in the Polaris Flare. This cloud contains five starless cores. Using the spectral synthesis code Cloudy, we explore uncertainties in the derivation of column densities, and hence masses of molecular cores from Herschel data. We first consider several detailed grain models that predict far-infrared grain opacities. Opacities predicted by the models differ by more than a factor of two, leading to uncertainties in derived column densities by the same factor. Then we consider uncertainties associated with the modified blackbody fitting process used by observers to estimate column densities. …
Observational Properties Of Simulated Galaxies In Overdense And Average Regions At Redshifts Z ≃ 6–12, Hidenobu Yajima, Isaac Shlosman, Emilio Romano-Díaz, Kentaro Nagamine
Observational Properties Of Simulated Galaxies In Overdense And Average Regions At Redshifts Z ≃ 6–12, Hidenobu Yajima, Isaac Shlosman, Emilio Romano-Díaz, Kentaro Nagamine
Physics and Astronomy Faculty Publications
We use high-resolution zoom-in cosmological simulations of galaxies of Romano-Díaz et al., post-processing them with a panchromatic three-dimensional radiation transfer code to obtain the galaxy UV luminosity function (LF) at z ≃ 6–12. The galaxies are followed in a rare, heavily overdense region within a ∼5σ density peak, which can host high-z quasars, and in an average density region, down to the stellar mass of Mstar ∼ 4 × 107 M⊙. We find that the overdense regions evolve at a substantially accelerated pace – the most massive galaxy has grown to Mstar ∼ 8.4 …
Variability Of The Coronal Line Region In Ngc 4151, Hermine Landt, Martin J. Ward, Katrien C. Steenbrugge, Gary J. Ferland
Variability Of The Coronal Line Region In Ngc 4151, Hermine Landt, Martin J. Ward, Katrien C. Steenbrugge, Gary J. Ferland
Physics and Astronomy Faculty Publications
We present the first extensive study of the coronal line variability in an active galaxy. Our data set for the nearby source NGC 4151 consists of six epochs of quasi-simultaneous optical and near-infrared spectroscopy spanning a period of about 8 yr and five epochs of X-ray spectroscopy overlapping in time with it. None of the coronal lines showed the variability behaviour observed for the broad emission lines and hot dust emission. In general, the coronal lines varied only weakly, if at all. Using the optical [Fe vii] and X-ray O vii emission lines we estimate that the coronal line gas …
Stellar Spectroscopy: New Methods And Insights, Sanaz S. Golriz
Stellar Spectroscopy: New Methods And Insights, Sanaz S. Golriz
Electronic Thesis and Dissertation Repository
The study of the chemical evolution of stars is of crucial importance since they play a major role in the enrichment of the chemistry of the universe. Throughout their lifetime, stars undergo several processes that can alter their chemistry. Gradually, the nucleosynthesis products from the interior of the star are radiatively and convectively levitated and mixed with the upper layers of the atmosphere. In the later stages of their evolution, low to intermediate mass stars (0.8-8.0~M☉) eject a significant fraction of these nucleosynthesis products, resulting in a circumstellar envelope of gas and dust around the central star with a very …
High-Resolution Image Reconstruction From A Sequence Of Rotated And Translated Frames And Its Application To An Infrared Imaging System, Russell C. Hardie, Kenneth J. Barnard, John G. Bognar, Ernest E. Armstrong, Edward A. Watson
High-Resolution Image Reconstruction From A Sequence Of Rotated And Translated Frames And Its Application To An Infrared Imaging System, Russell C. Hardie, Kenneth J. Barnard, John G. Bognar, Ernest E. Armstrong, Edward A. Watson
Russell C. Hardie
Some imaging systems employ detector arrays that are not sufficiently dense to meet the Nyquist criterion during image acquisition. This is particularly true for many staring infrared imagers. Thus, the full resolution afforded by the optics is not being realized in such a system. This paper presents a technique for estimating a high-resolution image, with reduced aliasing, from a sequence of undersampled rotated and translationally shifted frames. Such an image sequence can be obtained if an imager is mounted on a moving platform, such as an aircraft. Several approaches to this type of problem have been proposed in the literature. …
Synchrotron Based Infrared Microspectroscopy Of Carbonaceous Chondrites., Mehmet Yesiltas
Synchrotron Based Infrared Microspectroscopy Of Carbonaceous Chondrites., Mehmet Yesiltas
Electronic Theses and Dissertations
Relationships between organic molecules and inorganic minerals are investigated in five carbonaceous chondrites, Northwest Africa 852 (CR2), Tagish Lake (C2-ungroupped), Orgueil (CI1), Sutter's Mill (CM), and Murchison (CM2), with micron spatial resolution using synchrotron-based imaging micro-FTIR spectroscopy. Correlations based on absorption strength for various constituents are determined using statistical correlation analysis. Silicate band is found to be positively correlated with stretching modes of aliphatic hydrocarbons in NWA 852 and Tagish Lake. The former is highly correlated with the hydration band in all meteorites. Negative correlation is observed between water+organics and carbonate bands in all meteorites. Two dimensional infrared maps for …