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Physical Sciences and Mathematics Commons™
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Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
A Catalog Of Visual-Like Morphologies In The 5 Candels Fields Using Deep Learning, M. Huertas-Company, R. Gravet, G. Cabrera-Vives, Pablo G. Pérez-González, J. Kartaltepe, Guillermo Barro, M. Bernardi, S. Mei, F. Shankar, P. Dimauro, E. F. Bell, Dale D. Kocevski, David C. Koo, Sandra M. Faber, Daniel H. Mcintosh
A Catalog Of Visual-Like Morphologies In The 5 Candels Fields Using Deep Learning, M. Huertas-Company, R. Gravet, G. Cabrera-Vives, Pablo G. Pérez-González, J. Kartaltepe, Guillermo Barro, M. Bernardi, S. Mei, F. Shankar, P. Dimauro, E. F. Bell, Dale D. Kocevski, David C. Koo, Sandra M. Faber, Daniel H. Mcintosh
Physics and Astronomy Faculty Publications
We present a catalog of visual-like H-band morphologies of ~50.000 galaxies (Hf160w < 24.5) in the 5 CANDELS fields (GOODS-N, GOODS-S, UDS, EGS, and COSMOS). Morphologies are estimated using Convolutional Neural Networks (ConvNets). The median redshift of the sample is 〈z〉 ~ 1.25. The algorithm is trained on GOODS-S, for which visual classifications are publicly available, and then applied to the other 4 fields. Following the CANDELS main morphology classification scheme, our model retrieves for each galaxy the probabilities of having a spheroid or a disk, presenting an irregularity, being compact or a point source, and being unclassifiable. ConvNets are able to predict the fractions of votes given to a galaxy image with zero bias and ~10% scatter. The fraction of mis-classifications is …
Reionization After Planck : The Derived Growth Of The Cosmic Ionizing Emissivity Now Matches The Growth Of The Galaxy Uv Luminosity Density., R. J. Bouwens, G. D. Illingworth, P. A. Oesch, J. Caruana, Benne W. Holwerda, R. Smit, S. M. Wilkins
Reionization After Planck : The Derived Growth Of The Cosmic Ionizing Emissivity Now Matches The Growth Of The Galaxy Uv Luminosity Density., R. J. Bouwens, G. D. Illingworth, P. A. Oesch, J. Caruana, Benne W. Holwerda, R. Smit, S. M. Wilkins
Faculty Scholarship
Thomson optical depth τ measurements from Planck provide new insights into the reionization of the universe. In pursuit of model-independent constraints on the properties of the ionizing sources, we determine the empirical evolution of the cosmic ionizing emissivity. We use a simple two-parameter model to map out the evolution in the emissivity at z 6 from the new Planck optical depth τ measurements, from the constraints provided by quasar absorption spectra and from the prevalence of Lyα emission in z ∼ 7–8 galaxies. We find the redshift evolution in the emissivity Nion z ˙ ( ) required by the …
The Sizes Of Candidate Z~9-10 Galaxies : Confirmation Of The Bright Candels Sample And Relation With Luminosity And Mass., Benne W. Holwerda, R. J. Bouwens, P. A. Oesch, R. Smit, G. D. Illingworth, I. Labbe
The Sizes Of Candidate Z~9-10 Galaxies : Confirmation Of The Bright Candels Sample And Relation With Luminosity And Mass., Benne W. Holwerda, R. J. Bouwens, P. A. Oesch, R. Smit, G. D. Illingworth, I. Labbe
Faculty Scholarship
Recently, a small sample of six z ∼ 9–10 candidates was discovered in CANDELS that are ~-´ 10 20 more luminous than any of the previous z ∼ 9–10 galaxies identified over the HUDF/XDF and CLASH fields. We measure the sizes of these candidates to map out the size evolution of galaxies from the earliest observable times. Their sizes are also used to provide a valuable constraint on whether these unusual galaxy candidates are at high redshift. Using galfit to derive sizes from the CANDELS F160W images of these candidates, we find a mean size of 0. 13 0. 0 …
Uv Luminosity Functions At Redshifts Z~4 To Z~10 : 10,000 Galaxies From Hst Legacy Fields., R. J. Bouwens, G. D. Illingworth, P. A. Oesch, M. Trenti, I. Labbe, L. Bradley, C. M. Carollo, P. G. Van Dokkum, V. Gonzalez, Benne W. Holwerda, M. Franx, L. Spitler, R. Smit, D. Magee
Uv Luminosity Functions At Redshifts Z~4 To Z~10 : 10,000 Galaxies From Hst Legacy Fields., R. J. Bouwens, G. D. Illingworth, P. A. Oesch, M. Trenti, I. Labbe, L. Bradley, C. M. Carollo, P. G. Van Dokkum, V. Gonzalez, Benne W. Holwerda, M. Franx, L. Spitler, R. Smit, D. Magee
Faculty Scholarship
The remarkable Hubble Space Telescope (HST) data sets from the CANDELS, HUDF09, HUDF12, ERS, and BoRG/HIPPIES programs have allowed us to map the evolution of the rest-frame UV luminosity function (LF) from z ~ 10 to z ~ 4. We develop new color criteria that more optimally utilize the full wavelength coverage from the optical, near-IR, and mid-IR observations over our search fields, while simultaneously minimizing the incompleteness and eliminating redshift gaps. We have identified 5859, 3001, 857, 481, 217, and 6 galaxy candidates at z ~ 4, z ~ 5, z ~ 6, z ~ 7, z ~ 8, …
High-Precision Photometric Redshifts From Spitzer/Irac : Extreme [3.6] - [4.5] Colors Identify Galaxies In The Redshift Range Z ~ 6.6 - 6.9., Renske Smit, Rychard J. Bouwens, Marijn Franx, Pascal A. Oesch, Matthew L. N. Ashby, S. P. Millner, Ivo Labbe, Benne W. Holwerda, Giovanni G. Fazio, J. S. Huang
High-Precision Photometric Redshifts From Spitzer/Irac : Extreme [3.6] - [4.5] Colors Identify Galaxies In The Redshift Range Z ~ 6.6 - 6.9., Renske Smit, Rychard J. Bouwens, Marijn Franx, Pascal A. Oesch, Matthew L. N. Ashby, S. P. Millner, Ivo Labbe, Benne W. Holwerda, Giovanni G. Fazio, J. S. Huang
Faculty Scholarship
One of the most challenging aspects of studying galaxies in the z 7 universe is the infrequent confirmation of their redshifts through spectroscopy, a phenomenon thought to occur from the increasing opacity of the intergalactic medium to Lyα photons at z > 6.5. The resulting redshift uncertainties inhibit the efficient search for [C II] in z ~ 7 galaxies with sub-millimeter instruments such as ALMA, given their limited scan speed for faint lines. One means by which to improve the precision of the inferred redshifts is to exploit the potential impact of strong nebular emission lines on the colors of …