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Articles 1 - 9 of 9
Full-Text Articles in Physical Sciences and Mathematics
Thick Disks Of Edge-On Galaxies Seen Through The Spitzer Survey Of Stellar Structure In Galaxies (S4g) : Lair Of Missing Baryons?, Sebastien Comeron, Bruce G. Elmegreen, Johan H. Knapen, Heikki Salo, Eija Laurikainen, Jarkko Laine, E. Athanassoula, Albert Bosma, Kartik Sheth, Michael W. Regan, Joannah L. Hinz, Armando Gil De Paz, Karin Menendez-Delmestre, Trisha Mizusawa, Juan Carlos Munoz-Mateos, Mark Seibert, Taehyun Kim, Debra M. Elmegreen, Dimitri A. Gadotti, Luis C. Ho, Benne W. Holwerda, Jani Lappalainen, Eva Schinnerer, Ramin Skibba
Thick Disks Of Edge-On Galaxies Seen Through The Spitzer Survey Of Stellar Structure In Galaxies (S4g) : Lair Of Missing Baryons?, Sebastien Comeron, Bruce G. Elmegreen, Johan H. Knapen, Heikki Salo, Eija Laurikainen, Jarkko Laine, E. Athanassoula, Albert Bosma, Kartik Sheth, Michael W. Regan, Joannah L. Hinz, Armando Gil De Paz, Karin Menendez-Delmestre, Trisha Mizusawa, Juan Carlos Munoz-Mateos, Mark Seibert, Taehyun Kim, Debra M. Elmegreen, Dimitri A. Gadotti, Luis C. Ho, Benne W. Holwerda, Jani Lappalainen, Eva Schinnerer, Ramin Skibba
Faculty Scholarship
Most, if not all, disk galaxies have a thin (classical) disk and a thick disk. In most models thick disks are thought to be a necessary consequence of the disk formation and/or evolution of the galaxy. We present the results of a study of the thick disk properties in a sample of carefully selected edge-on galaxies with types ranging from T = 3 to T = 8. We fitted one-dimensional luminosity profiles with physically motivated functions—the solutions of two stellar and one gaseous isothermal coupled disks in equilibrium—which are likely to yield more accurate results than other functions used in …
Quantified H I Morphology – I. Multi-Wavelength Analysis Of The Things Galaxies., Benne W. Holwerda, N. Pirzkal, W. J. G. De Blok, A. Bouchard, S. -L. Blyth, K. J. Van Der Heyden, E. C. Elson
Quantified H I Morphology – I. Multi-Wavelength Analysis Of The Things Galaxies., Benne W. Holwerda, N. Pirzkal, W. J. G. De Blok, A. Bouchard, S. -L. Blyth, K. J. Van Der Heyden, E. C. Elson
Faculty Scholarship
Galaxy evolution is driven to a large extent by interactions and mergers with other galaxies and the gas in galaxies is extremely sensitive to the interactions. One method to measure such interactions uses the quantified morphology of galaxy images. Well-established parameters are Concentration, Asymmetry, Smoothness, Gini and M20 of a galaxy image. Thus far, the application of this technique has mostly been restricted to rest-frame ultraviolet and optical images. However, with the new radio observatories being commissioned [South African Karoo Array Telescope (MeerKAT), Australian SKA Pathfinder (ASKAP), Extended Very Large Array (EVLA), Westerbork Synthesis Radio Telescope/APERture Tile In Focus instrument …
Quantified H I Morphology – Ii. Lopsidedness And Interaction In Whisp Column Density Maps., Benne W. Holwerda, N. Pirzkal, W. J. G. De Blok, A. Bouchard, S. -L. Blyth, K. J. Van Der Heyden, E. C. Elson
Quantified H I Morphology – Ii. Lopsidedness And Interaction In Whisp Column Density Maps., Benne W. Holwerda, N. Pirzkal, W. J. G. De Blok, A. Bouchard, S. -L. Blyth, K. J. Van Der Heyden, E. C. Elson
Faculty Scholarship
Lopsidedness of the gaseous disc of spiral galaxies is a common phenomenon in disc morphology, profile and kinematics. Simultaneously, the asymmetry of a galaxy’s stellar disc, in combination with other morphological parameters, has seen extensive use as an indication of recent merger or interaction in galaxy samples. Quantified morphology of stellar spiral discs is one avenue to determine the merger rate over much of the age of the Universe. In this paper, we measure the quantitative morphology parameters for the H I column density maps from the Westerbork observations of neutral Hydrogen in Irregular and SPiral galaxies (WHISP). These are …
Quantified H I Morphology – V. H I Discs In The Virgo Cluster., Benne W. Holwerda, N. Pirzkal, W. J. G. De Blok, W. Van Driel
Quantified H I Morphology – V. H I Discs In The Virgo Cluster., Benne W. Holwerda, N. Pirzkal, W. J. G. De Blok, W. Van Driel
Faculty Scholarship
We explore the quantified morphology of atomic hydrogen (H i) discs in the Virgo cluster. These galaxies display a wealth of phenomena in their H i morphology, e.g., tails, truncation and warps. These morphological disturbances are related to the ram pressure stripping and tidal interaction that galaxies undergo in this dense cluster environment. To quantify the morphological transformation of the H i discs, we compute the morphological parameters of Concentration, Asymmetry, Smoothness, Gini and M20 and our own GM for 51 galaxies in 48 H i column density maps from the VLA Imaging of Virgo spirals in Atomic gas (VIVA) …
Quantified H I Morphology – Iii. Merger Visibility Times From H I In Galaxy Simulations., Benne W. Holwerda, N. Pirzkal, T. J. Cox, W. J. G. De Blok, J. Weniger, A. Bouchard, S. -L. Blyth, K. J. Van Der Heyden
Quantified H I Morphology – Iii. Merger Visibility Times From H I In Galaxy Simulations., Benne W. Holwerda, N. Pirzkal, T. J. Cox, W. J. G. De Blok, J. Weniger, A. Bouchard, S. -L. Blyth, K. J. Van Der Heyden
Faculty Scholarship
Major mergers of disc galaxies are thought to be a substantial driver in galaxy evolution. To trace the fraction and rate of galaxy mergers over cosmic times, several observational techniques have been developed over the last decade, including parametrized morphological selection. We apply this morphological selection of mergers to 21 cm radio emission line (H I) column density images of spiral galaxies in nearby surveys. In this paper, we investigate how long a 1:1 merger is visible in H I from N-body simulations. We evaluate the merger visibility times for selection criteria based on four parameters: Concentration, Asymmetry, M20 and …
Quantified H I Morphology – Iv. The Merger Fraction And Rate In Whisp., Benne W. Holwerda, N. Pirzkal, W. J. G. De Blok, A. Bouchard, S. -L. Blyth, K. J. Van Der Heyden
Quantified H I Morphology – Iv. The Merger Fraction And Rate In Whisp., Benne W. Holwerda, N. Pirzkal, W. J. G. De Blok, A. Bouchard, S. -L. Blyth, K. J. Van Der Heyden
Faculty Scholarship
The morphology of the atomic hydrogen (H I) disc of a spiral galaxy is the first component to be disturbed by a gravitational interaction such as a merger between two galaxies. We use a simple parametrization of the morphology of H I column density maps of the Westerbork observations of neutral Hydrogen in Irregular and SPiral galaxies (WHISP) project to select those galaxies that are likely undergoing a significant interaction. Merging galaxies occupy a particular part of parameter space defined by Asymmetry (A), the relative contribution of the 20 per cent brightest pixels to the second-order moment of the column …
The Unusual Vertical Mass Distribution Of Ngc 4013 Seen Through The Spitzer Survey Of Stellar Structure In Galaxies (S4g)., Sebastien Comeron, Bruce G. Elmegreen, Johan H. Knapen, Kartik Sheth, Joannah L. Hinz, Michael W. Regan, Armando Gil De Paz, Juan Carlos Munoz-Mateos, Karin Menendez-Delmestre, Mark Seibert, Taehyun Kim, Trisha Mizusawa, Eija Laurikainen, Heikki Salo, Jarkko Laine, E. Athanassoula, Albert Bosma, Ronald J. Buta, Dimitri A. Gadotti, Luis C. Ho, Benne W. Holwerda, Eva Schinnerer, Dennis Zaritsky
The Unusual Vertical Mass Distribution Of Ngc 4013 Seen Through The Spitzer Survey Of Stellar Structure In Galaxies (S4g)., Sebastien Comeron, Bruce G. Elmegreen, Johan H. Knapen, Kartik Sheth, Joannah L. Hinz, Michael W. Regan, Armando Gil De Paz, Juan Carlos Munoz-Mateos, Karin Menendez-Delmestre, Mark Seibert, Taehyun Kim, Trisha Mizusawa, Eija Laurikainen, Heikki Salo, Jarkko Laine, E. Athanassoula, Albert Bosma, Ronald J. Buta, Dimitri A. Gadotti, Luis C. Ho, Benne W. Holwerda, Eva Schinnerer, Dennis Zaritsky
Faculty Scholarship
NGC 4013 is a nearby Sb edge-on galaxy known for its “prodigious” H i warp and its “giant” tidal stream. Previous work on this unusual object shows that it cannot be fitted satisfactorily by a canonical thin+thick disk structure. We have produced a new decomposition of NGC 4013, considering three stellar flattened components (thin+thick disk plus an extra and more extended component) and one gaseous disk. All four components are considered to be gravitationally coupled and isothermal. To do so, we have used the 3.6μm images from the Spitzer Survey of Stellar Structure in Galaxies. We find evidence for NGC …
The Ghosts Survey. I. Hubble Space Telescope Advanced Camera For Surveys Data., D. J. Radburn-Smith, R. S. De Jong, A. C. Seth, J. Bailin, E. F. Bell, T. M. Brown, J. S. Bullock, S. Courteau, J. J. Dalcanton, H. C. Ferguson, P. Goudfrooij, S. Holfeltz, Benne W. Holwerda, C. Purcell, J. Sick, D. Streich, M. Vlajic, D. B. Zucker
The Ghosts Survey. I. Hubble Space Telescope Advanced Camera For Surveys Data., D. J. Radburn-Smith, R. S. De Jong, A. C. Seth, J. Bailin, E. F. Bell, T. M. Brown, J. S. Bullock, S. Courteau, J. J. Dalcanton, H. C. Ferguson, P. Goudfrooij, S. Holfeltz, Benne W. Holwerda, C. Purcell, J. Sick, D. Streich, M. Vlajic, D. B. Zucker
Faculty Scholarship
We present an overview of the GHOSTS survey, the largest study to date of the resolved stellar populations in the outskirts of disk galaxies. The sample consists of 14 disk galaxies within 17 Mpc, whose outer disks and halos are imaged with the Hubble Space Telescope Advanced Camera for Surveys (ACS). In the first paper of this series, we describe the sample, explore the benefits of using resolved stellar populations, and discuss our ACS F606W and F814W photometry. We use artificial star tests to assess completeness and use overlapping regions to estimate photometric uncertainties. The median depth of the survey …
The Thick Disk In The Galaxy Ngc 4244 From S4g Imaging., Sebastien Comeron, Johan H. Knapen, Kartik Sheth, Michael Regan, Joannah L. Hinz, Armando Gil De Paz, Karin Menendez-Delmestre, Juan Carlos Munoz-Mateos, Mark Seibert, Taehyun Kim, E. Athanassoula, Albert Bosma, Ronald J. Buta, Bruce G. Elmegreen, Luis C. Ho, Benne W. Holwerda, Eija Laurikainen, Heikki Salo, Eva Schinnerer
The Thick Disk In The Galaxy Ngc 4244 From S4g Imaging., Sebastien Comeron, Johan H. Knapen, Kartik Sheth, Michael Regan, Joannah L. Hinz, Armando Gil De Paz, Karin Menendez-Delmestre, Juan Carlos Munoz-Mateos, Mark Seibert, Taehyun Kim, E. Athanassoula, Albert Bosma, Ronald J. Buta, Bruce G. Elmegreen, Luis C. Ho, Benne W. Holwerda, Eija Laurikainen, Heikki Salo, Eva Schinnerer
Faculty Scholarship
If thick disks are ubiquitous and a natural product of disk galaxy formation and/or evolution processes, all undisturbed galaxies that have evolved during a significant fraction of a Hubble time should have a thick disk. The late-type spiral galaxy NGC 4244 has been reported as the only nearby edge-on galaxy without a confirmed thick disk. Using data from the Spitzer Survey of Stellar Structure in Galaxies (S4G) we have identified signs of two disk components in this galaxy. The asymmetries between the light profiles on both sides of the mid-plane of NGC 4244 can be explained by a combination of …