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Related papers: Predicting the Neutral Hydrogen Content of Galaxie…

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We have used the Parkes Multibeam system and the Sloan Digital Sky Survey (SDSS) to assemble a sample of 195 galaxies selected originally from their HI signature to avoid biases against unevolved or low surface brightness objects. For each…

Most galaxies in the nearby Universe are gravitationally bound to a cluster or group of galaxies. Their optical contents, such as optical richness, are crucial for understanding the co-evolution of galaxies and large-scale structures in…

Computer Vision and Pattern Recognition · Computer Science 2020-12-07 Gongbo Liang , Yuanyuan Su , Sheng-Chieh Lin , Yu Zhang , Yuanyuan Zhang , Nathan Jacobs

Understanding the impact of halo properties beyond halo mass on the clustering of galaxies (namely galaxy assembly bias) remains a challenge for contemporary models of galaxy clustering. We explore the use of machine learning to predict the…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-15 Xiaoju Xu , Saurabh Kumar , Idit Zehavi , Sergio Contreras

We report the first results of a programme aimed at studying the properties of high redshift galaxies with on-going massive and dominant episodes of star formation (HII galaxies). We use the $L(\mathrm{H}\beta) - \sigma$ distance estimator…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Roberto Terlevich , Elena Terlevich , Jorge Melnick , Ricardo Chávez , Manolis Plionis , Fabio Bresolin , Spyros Basilakos

We review theoretical approaches to the study of galaxy formation, with emphasis on the role of hydrodynamic simulations in modeling the high redshift galaxy population. We present new predictions for the abundance of star-forming galaxies…

Astrophysics · Physics 2007-05-23 David H. Weinberg , Romeel Dave' , Jeffrey P. Gardner , Lars Hernquist , Neal Katz

Environmental effects within cosmological overdensities, such as galaxy groups and clusters, have been shown to impact galaxies and their cold gas reservoirs and thereby provide constraints on galaxy evolution models. Galaxy groups foster…

Astrophysics of Galaxies · Physics 2025-09-10 G. Lawrie , R. P. Deane , R. Davè

Details are presented of the HI Jodrell All Sky Survey (HIJASS). HIJASS is a blind neutral hydrogen (HI) survey of the northern sky, being conducted using the multibeam receiver on the Lovell Telescope at Jodrell Bank. HIJASS covers the…

The intrinsic alignments (IA) of galaxies, regarded as a contaminant in weak lensing analyses, represents the correlation of galaxy shapes due to gravitational tidal interactions and galaxy formation processes. As such, understanding IA is…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-23 Sneh Pandya , Yuanyuan Yang , Nicholas Van Alfen , Jonathan Blazek , Robin Walters

Cold gas evolution ties the formation of dark matter halos to the star formation history of the universe. A primary component of cold gas, neutral atomic hydrogen (HI), can be traced by its 21-cm emission line. However, the faintness of…

Astrophysics of Galaxies · Physics 2024-07-12 Tariq Blecher , Roger Deane , Danail Obreschkow , Ian Heywood

We present a machine-learning framework to accurately characterize morphologies of Active Galactic Nucleus (AGN) host galaxies within $z<1$. We first use PSFGAN to decouple host galaxy light from the central point source, then we invoke the…

Observations of neutral hydrogen can provide a wealth of information about the distribution and kinematics of galaxies. To detect HI beyond the ionisation edge of galaxy disks, column density sensitivities have to be achieved that probe the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 A. Popping , R. Braun

Accurately modeling the cold gas content in the universe is challenging for current theoretical models. We propose a new empirical model NeutralUniverseMachine for the evolution of HI and H$_2$ gas along with dark matter halos based on the…

Astrophysics of Galaxies · Physics 2023-08-03 Hong Guo , Jing Wang , Michael G. Jones , Peter Behroozi

In modern astrophysics, the machine learning has increasingly gained more popularity with its incredibly powerful ability to make predictions or calculated suggestions for large amounts of data. We describe an application of the supervised…

Astrophysics of Galaxies · Physics 2018-12-26 Yu Bai , JiFeng Liu , Song Wang , Fan Yang

We study the evolution of the cold gas content of galaxies by splitting the interstellar medium into its atomic and molecular hydrogen components, using the galaxy formation model GALFORM in the LCDM framework. We calculate the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Claudia del P. Lagos , Carlton M. Baugh , Cedric G. Lacey , Andrew J. Benson , Han-Seek Kim , Chris Power

We investigate machine learning (ML) techniques for predicting the number of galaxies (N_gal) that occupy a halo, given the halo's properties. These types of mappings are crucial for constructing the mock galaxy catalogs necessary for…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Xiaoying Xu , Shirley Ho , Hy Trac , Jeff Schneider , Barnabas Poczos , Michelle Ntampaka

The application of artificial neural networks (ANNs) for the estimation of HI gas mass fraction (\fgas) is investigated, based on a sample of 13,674 galaxies in the Sloan Digital Sky Survey (SDSS) with HI detections or upper limits from the…

Astrophysics of Galaxies · Physics 2016-12-07 Hossen Teimoorinia , Sara L. Ellison , David R. Patton

We present the design and methods of the COS-Halos survey, a systematic investigation of the gaseous halos of 44 z = 0.15-0.35 galaxies using background QSOs observed with the Cosmic Origins Spectrograph aboard the Hubble Space Telescope.…

Using the L-Galaxies semi-analytic model we simultaneously fit the HI mass function, stellar mass function and galaxy colours. We find good fits to all three observations at z = 0 and to the stellar mass function and galaxy colours at z =…

Astrophysics of Galaxies · Physics 2017-09-27 Hazel Martindale , Peter A. Thomas , Bruno M. Henriques , Jon Loveday

Using star-forming galaxies sample in the nearby Universe (0.02<z<0.10) selected from the SDSS (DR7) and GALEX all-sky survey (GR5), we present a new empirical calibration for predicting dust extinction of galaxies from H-alpha-to-FUV flux…