Physical Sciences and Mathematics | Open Access Articles

A Search For Optical Afterglow From Grb 970828, P. J. Groot, T. J. Galama, J. Van Paradijs, C. Kouveliotou, R. A. M. J. Wijers, J. Bloom, N. Tanvir, R. Vanderspek, J. Greiner, A. J. Castro-Tirado, J. Gorosabel, T. Von Hippel, M. Lehnert, K. Kuijken, H. Hoekstra, N. Metcalfe, C. Howk, C. Conselice, J. Telting, R. G. M. Rutten, J. Rhoads, A. Cole, D. J. Pisano, R. Naber, R. Schwarz

Ted von Hippel

We report on the results of R-band observations of the error box of the g-ray burst of 1997 August 28 made between 4 hr and 8 days after this burst occurred. No counterpart was found varying by more than 0.2 mag down to R 5 23.8. We discuss the consequences of this nondetection for relativistic blast wave models of g-ray bursts and the possible effect of redshift on the relation between optical absorption and the low-energy cutoff in the X-ray afterglow spectrum.

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Morphological Parameters Of A Spitzer Survey Of Stellar Structure In Galaxies., Benne W. Holwerda, J. C. Munoz-Mateos, S. Comeron, S. Meidt, K. Sheth, S. Laine, J. L. Hinz, M. W. Regan, A. Gil De Paz, K. Menendez-Delmestre, M. Seibert, T. Kim, T. Mizusawa, E. Laurikainen, H. Salo, J. Laine, D. A. Gadotti, D. Zaritsky, S. Erroz-Ferrer, L. C. Ho, J. H. Knapen, E. Athanassoula, A. Bosma, N. Pirzkal

Benne Holwerda

The morphology of galaxies can be quantified to some degree using a set of scale-invariant parameters. Concentration (C), asymmetry (A), smoothness (S), the Gini index (G), the relative contribution of the brightest pixels to the secondorder moment of the flux (M20), ellipticity (E), and the Gini index of the second-order moment (GM) have all been applied to morphologically classify galaxies at various wavelengths. Here, we present a catalog of these parameters for the Spitzer Survey of stellar structure in Galaxies, a volume-limited, near-infrared (NIR) imaging survey of nearby galaxies using the 3.6 and 4.5μm channels of the Infrared Array Camera …

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Galaxy And Mass Assembly (Gama) : End Of Survey Report And Data Release 2., J. Liske, I. K. Baldry, S. P. Driver, R. J. Tuffs, M. Alpaslan, E. Andrae, S. Brough, M. E. Cluver, M. W. Grootes, M. L. P. Gunawardhana, L. S. Kelvin, J. Loveday, A. S. G. Robotham, E. N. Taylor, S. P. Bamford, J. Bland-Hawthorn, M. J. I. Brown, M. J. Drinkwater, A. M. Hopkins, M. Meyer, P. Norberg, J. A. Peacock, N. K. Agius, S. K. Andrews, A. E. Bauer, J. H. Y. Ching, M. Colless, C. J. Conselice, S. M. Croom, L. J. M. Davies, R. De Propris, L. Dunne, E. M. Eardley, S. Ellis, C. Foster, C. S. Frenk, B. Haußler, Benne W. Holwerda, C. Howlett, H. Ibarra, M. J. Jarvis, D. H. Jones, P. R. Kafle, C. G. Lacey, R. Lange, M. Lara-Lopez, Angel R. Lopez-Sanchez, S. J. Maddox, B. F. Madore, T. Mcnaught-Roberts, A. J. Moffett, R. C. Nichol, M. S. Owers, D. Palamara, S. J. Penny, S. Phillipps, K. A. Pimbblet, C. C. Popescu, M. Prescott, R. Proctor, E. M. Sadler, A. E. Sansom, M. Seibert, R. Sharp, W. Sutherland, J. A. Vazquez-Mata, E. Van Kampen, S. M. Wilkins, R. Williams, A. H. Wright

Benne Holwerda

The Galaxy And Mass Assembly (GAMA) survey is one of the largest contemporary spectroscopic surveys of low redshift galaxies. Covering an area of ∼286 deg2 (split among five survey regions) down to a limiting magnitude of r < 19.8 mag, we have collected spectra and reliable redshifts for 238 000 objects using the AAOmega spectrograph on the Anglo-Australian Telescope. In addition, we have assembled imaging data from a number of independent surveys in order to generate photometry spanning the wavelength range 1 nm–1 m. Here, we report on the recently completed spectroscopic survey and present a series of diagnostics to assess …

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Galaxy And Mass Assembly (Gama) : The Wavelength Dependence Of Galaxy Structure Versus Redshift And Luminosity., Rebecca Kennedy, Steven P. Bamford, Ivan K. Baldry, Boris Haußler, Benne W. Holwerda, Andrew M. Hopkins, Lee S. Kelvin, Rebecca Lange, Amanda J. Moffett, Cristina C. Popescu, Edward N. Taylor, Richard Tuffs, Marina Vika, Benedetta Vulcani

Benne Holwerda

We study how the sizes and radial profiles of galaxies vary with wavelength, by fitting Sersic ´ functions simultaneously to imaging in nine optical and near-infrared bands. To quantify the wavelength dependence of effective radius we use the ratio, R, of measurements in two rest-frame bands. The dependence of Sersic index on wavelength, ´ N , is computed correspondingly. Vulcani et al. have demonstrated that different galaxy populations present sharply contrasting behaviour in terms of R and N . Here we study the luminosity dependence of this result. We find that at higher luminosities, early-type galaxies display a more substantial …

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Galaxy And Mass Assembly (Gama) : The Bright Void Galaxy Population In The Optical And Mid-Ir., S. J. Penny, M. J. I. Brown, K. A. Pimbblet, M. E. Cluver, D. J. Croton, M. S. Owers, R. Lange, M. Alpaslan, I. K. Baldry, J. Bland-Hawthorn, S. Brough, S. P. Driver, Benne W. Holwerda, A. M. Hopkins, T. H. Jarrett, D. Heath Jones, L. S. Kelvin, M. A. Lara-Lopez, J. Liske, Angel R. Lopez-Sanchez, J. Loveday, M. Meyer, P. Norberg, A. S. G. Robotham, M. Rodrigues

Benne Holwerda

We examine the properties of galaxies in the Galaxies and Mass Assembly (GAMA) survey located in voids with radii >10 h−1 Mpc. Utilizing the GAMA equatorial survey, 592 void galaxies are identified out to z ≈ 0.1 brighter than Mr = −18.4, our magnitude completeness limit. Using the WHα versus [N ii]/Hα (WHAN) line strength diagnostic diagram, we classify their spectra as star forming, AGN, or dominated by old stellar populations. For objects more massive than 5 × 109 M⊙, we identify a sample of 26 void galaxies with old stellar populations classed as passive and retired galaxies in the …

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The Dependence Of The Av Prior For Sn Ia On Host Mass And Disc Inclination., Benne W. Holwerda, W. C. Keel, M. A. Kenworthy, K. J. Mack

Benne Holwerda

Type Ia supernovae (SNe Ia) are used as ‘standard candles’ for cosmological distance scales. To fit their light-curve shape–absolute luminosity relation, one needs to assume an intrinsic colour and a likelihood of host galaxy extinction or a convolution of these, a colour distribution prior. The host galaxy extinction prior is typically assumed to be an exponential drop-off for the current supernova programmes ( P(AV)∝e−AV/τ0" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; font-variant: inherit; font-stretch: inherit; line-height: normal; font-family: inherit; vertical-align: baseline; display: inline-table; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: …

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Galaxy And Mass Assembly (Gama) : Panchromatic Data Release (Far-Uv–Far-Ir) And The Low-Z Energy Budget., Simon P. Driver, Angus H. Wright, Stephen K. Andrews, Luke J. M. Davies, Prajwal R. Kafle, Rebecca Lange, Amanda J. Moffett, Elizabeth Mannering, Aaron S. G. Robotham, Kevin Vinsen, Mehmet Alpaslan, Ellen Andrae, Ivan K. Baldry, Amanda E. Bauer, Steven P. Bamford, Joss Bland-Hawthorn, Nathan Bourne, Sarah Brough, Michael J. I. Brown, Michelle Cluver, Scott M. Croom, Matthew Colless, Christopher J. Conselice, Elisabete Da Cunha, Roberto De Propris, Michael Drinkwater, Loretta Dunne, Steve Eales, Alastair Edge, Carlos Frenk, Alister W. Graham, Meiert Grootes, Benne W. Holwerda, Andrew M. Hopkins, Edo Ibar, Eelco Van Kampen, Lee S. Kelvin, Tom Jarrett, D. Heath Jones, Maritza A. Lara-Lopez, Jochen Liske, Angel R. Lopez-Sanchez, Jon Loveday, Steve J. Maddox, Barry Madore, Smriti Mahajan, Martin Meyer, Peder Norberg, Samantha J. Penny, Steven Phillipps, Cristina C. Popescu, Richard Tuffs, John A. Peacock, Kevin A. Pimbblet, Matthew Prescott, Kate Rowlands, Anne E. Sansom, Mark Seibert, Matthew W. L. Smith, Will J. Sutherland, Edward N. Taylor, Elisabetta Valiante, J. Antonio Vazquez-Mata, Lingyu Wang, Stephen M. Wilkins, Richard P. Williams

Benne Holwerda

We present the Galaxy And Mass Assembly (GAMA) Panchromatic Data Release (PDR) constituting over 230 deg2 of imaging with photometry in 21 bands extending from the far-UV to the far-IR. These data complement our spectroscopic campaign of over 300k galaxies, and are compiled from observations with a variety of facilities including: GALaxy Evolution eXplorer, Sloan Digital Sky Survey, Visible and Infrared Telescope for Astronomy (VISTA), Wide-field Infrared Survey Explorer, and Herschel, with the GAMA regions currently being surveyed by VLT Survey Telescope (VST) and scheduled for observations by Australian Square Kilometer Array Pathfinder (ASKAP). These data are processed to a …

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Galaxy And Mass Assembly (Gama) : Understanding The Wavelength Dependence Of Galaxy Structure With Bulge-Disc Decompositions., Rebecca Kennedy, Steven P. Bamford, Boris Haußler, Ivan K. Baldry, Malcolm Bremer, Sarah Brough, Michael J. I. Brown, Simon P. Driver, Kenneth Duncan, Alister W. Graham, Benne W. Holwerda, Andrew M. Hopkins, Lee S. Kelvin, Rebecca Lange, Steven Phillipps, Marina Vika, Benedetta Vulcani

Benne Holwerda

With a large sample of bright, low-redshift galaxies with optical–near-IR imaging from the GAMA survey we use bulge-disc decompositions to understand the wavelength-dependent behaviour of single-Sérsic structural measurements. We denote the variation in single-Sérsic index with wavelength as N N , likewise for effective radius we use R R . We find that most galaxies with a substantial disc, even those with no discernable bulge, display a high value of N N . The increase in Sérsic index to longer wavelengths is therefore intrinsic to discs, apparently resulting from radial variations in stellar population and/or dust reddening. Similarly, low values …

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Galaxy And Mass Assembly : Accurate Panchromatic Photometry From Optical Priors Using Lambdar., A. H. Wright, A. S. G. Robotham, N. Bourne, S. P. Driver, L. Dunne, S. J. Maddox, M. Alpaslan, S. K. Andrews, A. E. Bauer, J. Bland-Hawthorn, Sarah Brough, M. J. I. Brown, C. Clarke, Michelle Cluver, L. J. M. Davies, M. W. Grootes, Benne W. Holwerda, A. M. Hopkins, T. H. Jarrett, Prajwal R. Kafle, Rebecca Lange, J. Liske, J. Loveday, A. J. Moffett, P. Norberg, C. C. Popescu, M. Smith, E. N. Taylor, R. J. Tuffs, L. Wang, S. M. Wilkins

Benne Holwerda

We present the Lambda Adaptive Multi-Band Deblending Algorithm in R (LAMBDAR), a novel code for calculating matched aperture photometry across images that are neither pixel- nor PSF-matched, using prior aperture definitions derived from high-resolution optical imaging. The development of this program is motivated by the desire for consistent photometry and uncertainties across large ranges of photometric imaging, for use in calculating spectral energy distributions. We describe the program, specifically key features required for robust determination of panchromatic photometry: propagation of apertures to images with arbitrary resolution, local background estimation, aperture normalization, uncertainty determination and propagation, and object deblending. Using simulated …

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Galaxy And Mass Assembly (Gama) : Galaxy Colour Gradients Versus Colour, Structure, And Luminosity., Rebecca Kennedy, Steven P. Bamford, Boris Haußler, Sarah Brough, Benne W. Holwerda, Andrew M. Hopkins, Marina Vika, Benedetta Vulcani

Benne Holwerda

Using single-component fits to SDSS/UKIDSS images of galaxies in the G09 region of the GAMA survey we study radial colour gradients across the galaxy population. We use the multi-wavelength information provided by MegaMorph analysis of galaxy light profiles to calculate intrinsic colour gradients, and divide into six subsamples split by overall Sérsic index (n) and galaxy colour. We find a bimodality in the colour gradients of high- and low-n galaxies in all wavebands which varies with overall galaxy luminosity. Global trends in colour gradients therefore result from combining the contrasting behaviour of a number of different galaxy populations. The ubiquity …

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Full-Text Articles in Physical Sciences and Mathematics

Ted von Hippel

Benne Holwerda

Benne Holwerda

Benne Holwerda

Benne Holwerda

The Dependence Of The Av Prior For Sn Ia On Host Mass And Disc Inclination., Benne W. Holwerda, W. C. Keel, M. A. Kenworthy, K. J. Mack

Benne Holwerda

Benne Holwerda

Benne Holwerda

Benne Holwerda

Galaxy And Mass Assembly (Gama) : Galaxy Colour Gradients Versus Colour, Structure, And Luminosity., Rebecca Kennedy, Steven P. Bamford, Boris Haußler, Sarah Brough, Benne W. Holwerda, Andrew M. Hopkins, Marina Vika, Benedetta Vulcani

Benne Holwerda