Relevant bibliographies by topics / Photometric gaussian mixtures / Journal articles
To see the other types of publications on this topic, follow the link: Photometric gaussian mixtures.

Journal articles on the topic 'Photometric gaussian mixtures'

Author: Grafiati
Published: 1 June 2024
Last updated: 31 July 2025

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 35 journal articles for your research on the topic 'Photometric gaussian mixtures.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Crombez, Nathan, El Mustapha Mouaddib, Guillaume Caron, and Francois Chaumette. "Visual Servoing With Photometric Gaussian Mixtures as Dense Features." IEEE Transactions on Robotics 35, no. 1 (2019): 49–63. http://dx.doi.org/10.1109/tro.2018.2876765.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Hatfield, P. W., I. A. Almosallam, M. J. Jarvis, et al. "Augmenting machine learning photometric redshifts with Gaussian mixture models." Monthly Notices of the Royal Astronomical Society 498, no. 4 (2020): 5498–510. http://dx.doi.org/10.1093/mnras/staa2741.

Full text
Abstract:
ABSTRACT Wide-area imaging surveys are one of the key ways of advancing our understanding of cosmology, galaxy formation physics, and the large-scale structure of the Universe in the coming years. These surveys typically require calculating redshifts for huge numbers (hundreds of millions to billions) of galaxies – almost all of which must be derived from photometry rather than spectroscopy. In this paper, we investigate how using statistical models to understand the populations that make up the colour–magnitude distribution of galaxies can be combined with machine learning photometric redshif
APA, Harvard, Vancouver, ISO, and other styles
3

Jones, Daniel M., and Alan F. Heavens. "Gaussian mixture models for blended photometric redshifts." Monthly Notices of the Royal Astronomical Society 490, no. 3 (2019): 3966–86. http://dx.doi.org/10.1093/mnras/stz2687.

Full text
Abstract:
ABSTRACT Future cosmological galaxy surveys such as the Large Synoptic Survey Telescope (LSST) will photometrically observe very large numbers of galaxies. Without spectroscopy, the redshifts required for the analysis of these data will need to be inferred using photometric redshift techniques that are scalable to large sample sizes. The high number density of sources will also mean that around half are blended. We present a Bayesian photometric redshift method for blended sources that uses Gaussian mixture models to learn the joint flux–redshift distribution from a set of unblended training g
APA, Harvard, Vancouver, ISO, and other styles
4

Ansari, Zoe, Adriano Agnello, and Christa Gall. "Mixture models for photometric redshifts." Astronomy & Astrophysics 650 (June 2021): A90. http://dx.doi.org/10.1051/0004-6361/202039675.

Full text
Abstract:
Context. Determining photometric redshifts (photo-zs) of extragalactic sources to a high accuracy is paramount to measure distances in wide-field cosmological experiments. With only photometric information at hand, photo-zs are prone to systematic uncertainties in the intervening extinction and the unknown underlying spectral-energy distribution of different astrophysical sources, leading to degeneracies in the modern machine learning algorithm that impacts the level of accuracy for photo-z estimates. Aims. Here, we aim to resolve these model degeneracies and obtain a clear separation between
APA, Harvard, Vancouver, ISO, and other styles
5

Wagenveld, J. D., A. Saxena, K. J. Duncan, H. J. A. Röttgering, and M. Zhang. "Revealing new high-redshift quasar populations through Gaussian mixture model selection." Astronomy & Astrophysics 660 (April 2022): A22. http://dx.doi.org/10.1051/0004-6361/202142445.

Full text
Abstract:
We present a novel method for identifying candidate high-redshift quasars (HzQs; z ≳ 5.5) –which are unique probes of supermassive black hole growth in the early Universe– from large-area optical and infrared photometric surveys. Using Gaussian mixture models to construct likelihoods and incorporating informed priors based on population statistics, our method uses a Bayesian framework to assign posterior probabilities that differentiate between HzQs and contaminating sources. We additionally include deep radio data to obtain informed priors. Using existing HzQ data in the literature, we set a
APA, Harvard, Vancouver, ISO, and other styles
6

D’Isanto, A., and K. L. Polsterer. "Photometric redshift estimation via deep learning." Astronomy & Astrophysics 609 (January 2018): A111. http://dx.doi.org/10.1051/0004-6361/201731326.

Full text
Abstract:
Context. The need to analyze the available large synoptic multi-band surveys drives the development of new data-analysis methods. Photometric redshift estimation is one field of application where such new methods improved the results, substantially. Up to now, the vast majority of applied redshift estimation methods have utilized photometric features. Aims. We aim to develop a method to derive probabilistic photometric redshift directly from multi-band imaging data, rendering pre-classification of objects and feature extraction obsolete. Methods. A modified version of a deep convolutional netw
APA, Harvard, Vancouver, ISO, and other styles
7

Duncan, Kenneth J. "All-purpose, all-sky photometric redshifts for the Legacy Imaging Surveys Data Release 8." Monthly Notices of the Royal Astronomical Society 512, no. 3 (2022): 3662–83. http://dx.doi.org/10.1093/mnras/stac608.

Full text
Abstract:
ABSTRACT In this paper, we present photometric redshift (photo-z) estimates for the Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Surveys, currently the most sensitive optical survey covering the majority of the extragalactic sky. Our photo-z methodology is based on a machine-learning approach, using sparse Gaussian processes augmented with Gaussian mixture models (GMMs) that allow regions of parameter space to be identified and trained separately in a purely data-driven way. The same GMMs are also used to calculate cost-sensitive learning weights that mitigate biases in the spect
APA, Harvard, Vancouver, ISO, and other styles
8

Dinesh, Kadam, R. Madane Amol, Kutty Krishnan, and V. Bonde S. "Rain Streaks Elimination Using Image Processing Algorithms." Signal & Image Processing: An International Journal (SIPIJ) 10, no. 3 (2019): 21–32. https://doi.org/10.5281/zenodo.3351005.

Full text
Abstract:
The paper addresses the problem of rain streak removal from videos. While, Rain streak removal from scene is important but a lot of research in this area, robust and real time algorithms is unavailable in the market. Difficulties in the rain streak removal algorithm arises due to less visibility, less illumination, and availability of moving camera and objects. The challenge that plagues rain streak recovery algorithm is detecting rain streaks and replacing them with original values to recover the scene. In this paper, we discuss the use of photometric and chromatic properties for rain detecti
APA, Harvard, Vancouver, ISO, and other styles
9

Johnston, Harry, Nora Elisa Chisari, Shahab Joudaki, et al. "6 × 2 pt: Forecasting gains from joint weak lensing and galaxy clustering analyses with spectroscopic-photometric galaxy cross-correlations." Astronomy & Astrophysics 699 (July 2025): A127. https://doi.org/10.1051/0004-6361/202452466.

Full text
Abstract:
Accurate knowledge of galaxy redshift distributions is crucial in the inference of cosmological parameters from large-scale structure data. We explore the potential for enhanced self-calibration of photometric galaxy redshift distributions, n(z), through the joint analysis of up to six two-point functions. Our 3 × 2 pt configuration comprises photometric shear, spectroscopic galaxy clustering, and spectroscopic-photometric galaxy-galaxy lensing (GGL). We expand this to include spectroscopic-photometric cross-clustering, photometric GGL, and photometric auto-clustering, using the photometric sh
APA, Harvard, Vancouver, ISO, and other styles
10

Jang, J. K., Sukyoung K. Yi, Yohan Dubois, et al. "Translators of Galaxy Morphology Indicators between Observation and Simulation." Astrophysical Journal 950, no. 1 (2023): 4. http://dx.doi.org/10.3847/1538-4357/accd68.

Full text
Abstract:
Abstract Based on the recent advancements in numerical simulations of galaxy formation, we anticipate the achievement of realistic models of galaxies in the near future. Morphology is the most basic and fundamental property of galaxies, yet observations and simulations still use different methods to determine galaxy morphology, making it difficult to compare them. We hereby perform a test on the recent NewHorizon simulation, which has spatial and mass resolutions that are remarkably high for a large-volume simulation, to resolve the situation. We generate mock images for the simulated galaxies
APA, Harvard, Vancouver, ISO, and other styles
11

Feng, Yi, Yu Han, Xijing Zhang, Tanghui Li, Yanting Zhang, and Rui Fan. "ViPOcc: Leveraging Visual Priors from Vision Foundation Models for Single-View 3D Occupancy Prediction." Proceedings of the AAAI Conference on Artificial Intelligence 39, no. 3 (2025): 3004–12. https://doi.org/10.1609/aaai.v39i3.32308.

Full text
Abstract:
Inferring the 3D structure of a scene from a single image is an ill-posed and challenging problem in the field of vision-centric autonomous driving. Existing methods usually employ neural radiance fields to produce voxelized 3D occupancy, lacking instance-level semantic reasoning and temporal photometric consistency. In this paper, we propose ViPOcc, which leverages the visual priors from vision foundation models (VFMs) for fine-grained 3D occupancy prediction. Unlike previous works that solely employ volume rendering for RGB and depth image reconstruction, we introduce a metric depth estimati
APA, Harvard, Vancouver, ISO, and other styles
12

Escudero, Carlos G., Arianna Cortesi, Favio R. Faifer, et al. "The complex globular cluster system of the S0 galaxy NGC 4382 in the outskirts of the Virgo Cluster." Monthly Notices of the Royal Astronomical Society 511, no. 1 (2022): 393–412. http://dx.doi.org/10.1093/mnras/stac021.

Full text
Abstract:
ABSTRACT NGC 4382 is a merger-remnant galaxy that has been classified as morphological type E2, S0, and even Sa. In this work, we performed a photometric and spectroscopic analysis of the globular cluster (GC) system of this peculiar galaxy in order to provide additional information about its history. We used a combination of photometric data in different filters, and multiobject and long-slit spectroscopic data obtained using the Gemini/GMOS instrument. The photometric analysis of the GC system, using the Gaussian Mixture Model algorithm in the colour plane, reveals a complex colour distribut
APA, Harvard, Vancouver, ISO, and other styles
13

Tardugno Poleo, Valentina, Steven L. Finkelstein, Gene Leung, et al. "Identifying Active Galactic Nuclei at z ∼ 3 from the HETDEX Survey Using Machine Learning." Astronomical Journal 165, no. 4 (2023): 153. http://dx.doi.org/10.3847/1538-3881/acba92.

Full text
Abstract:
Abstract We used data from the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX) to study the incidence of AGN in continuum-selected galaxies at z ∼ 3. From optical and infrared imaging in the 24 deg2 Spitzer HETDEX Exploratory Large Area survey, we constructed a sample of photometric-redshift selected z ∼ 3 galaxies. We extracted HETDEX spectra at the position of 716 of these sources and used machine-learning methods to identify those which exhibited AGN-like features. The dimensionality of the spectra was reduced using an autoencoder, and the latent space was visualized through t-distri
APA, Harvard, Vancouver, ISO, and other styles
14

Jadhav, Vikrant V., Clara M. Pennock, Annapurni Subramaniam, Ram Sagar, and Prasanta Kumar Nayak. "UOCS – III. UVIT catalogue of open clusters with machine learning-based membership using Gaia EDR3 astrometry." Monthly Notices of the Royal Astronomical Society 503, no. 1 (2021): 236–53. http://dx.doi.org/10.1093/mnras/stab213.

Full text
Abstract:
ABSTRACT We present a study of six open clusters (Berkeley 67, King 2, NGC 2420, NGC 2477, NGC 2682, and NGC 6940), using the Ultra Violet Imaging Telescope (UVIT) aboard ASTROSAT and Gaia EDR3. We used combinations of astrometric, photometric, and systematic parameters to train and supervise a machine-learning algorithm along with a Gaussian mixture model for the determination of cluster membership. This technique is robust, reproducible, and versatile in various cluster environments. In this study, the Gaia EDR3 membership catalogues are provided along with classification of the stars as mem
APA, Harvard, Vancouver, ISO, and other styles
15

Reinhold, Timo, and Saskia Hekker. "Stellar rotation periods from K2 Campaigns 0–18." Astronomy & Astrophysics 635 (March 2020): A43. http://dx.doi.org/10.1051/0004-6361/201936887.

Full text
Abstract:
Context. Rotation period measurements of stars observed with the Kepler mission have revealed a lack of stars at intermediate rotation periods, accompanied by a decrease of photometric variability. Whether this so-called dearth region is a peculiarity of stars in the Kepler field, or reflects a general manifestation of stellar magnetic activity, is still under debate. The K2 mission has the potential to unravel this mystery by measuring stellar rotation and photometric variability along different fields in the sky. Aims. Our goal is to measure stellar rotation periods and photometric variabili
APA, Harvard, Vancouver, ISO, and other styles
16

Boudreaux, Emily M., Brian C. Chaboyer, Amanda Ash, Renata Edaes Hoh, and Gregory Feiden. "Chemically Self-consistent Modeling of the Globular Cluster NGC 2808 and its Effects on the Inferred Helium Abundance of Multiple Stellar Populations." Astrophysical Journal 980, no. 2 (2025): 180. https://doi.org/10.3847/1538-4357/ad9740.

Full text
Abstract:
Abstract The helium abundances in the multiple populations that are now known to comprise all closely studied Milky Way globular clusters (GCs) are often inferred by fitting isochrones generated from stellar evolutionary models to GC photometry. It is therefore important to build stellar models that are chemically self-consistent in terms of their structure, atmosphere, and opacity. In this work we present the first chemically self-consistent stellar models of the Milky Way GC NGC 2808 using MARCS model atmospheres, OPLIB high-temperature radiative opacities, and AESOPUS low-temperature radiat
APA, Harvard, Vancouver, ISO, and other styles
17

Peña Ramírez, K., C. González-Fernández, A.-N. Chené, and S. Ramírez Alegría. "The VVV open cluster project. Near-infrared sequences of NGC 6067, NGC 6259, NGC 4815, Pismis 18, Trumpler 23, and Trumpler 20." Monthly Notices of the Royal Astronomical Society 503, no. 2 (2021): 1864–76. http://dx.doi.org/10.1093/mnras/stab328.

Full text
Abstract:
ABSTRACT Open clusters are central elements of our understanding of the Galactic disc evolution, as an accurate determination of their parameters leads to an unbiased picture of our Galaxy’s structure. Extending the analysis towards fainter magnitudes in cluster sequences has a significant impact on the derived fundamental parameters, such as extinction and total mass. We perform a homogeneous analysis of six open stellar clusters in the Galactic disc using kinematic and photometric information from the Gaia DR2 and VVV surveys: NGC 6067, NGC 6259, NGC 4815, Pismis 18, Trumpler 23, and Trumple
APA, Harvard, Vancouver, ISO, and other styles
18

Escudero, Carlos G., Favio R. Faifer, Analía V. Smith Castelli, Mark A. Norris, and Juan C. Forte. "Field/isolated lenticular galaxies with high SN values: the case of NGC 4546 and its globular cluster system." Monthly Notices of the Royal Astronomical Society 493, no. 2 (2020): 2253–70. http://dx.doi.org/10.1093/mnras/staa392.

Full text
Abstract:
ABSTRACT We present a photometric study of the field lenticular galaxy NGC 4546 using Gemini/GMOS imaging in g′r′i′z′. We perform a 2D image decomposition of the surface brightness distribution of the galaxy using galfit, finding that four components adequately describe it. The subtraction of this model from our images and the construction of a colour map allow us to examine in great detail the asymmetric dust structures around the galactic centre. In addition, we perform a detailed analysis of the globular cluster (GC) system of NGC 4546. Using a Gaussian Mixture Model algorithm in the colour
APA, Harvard, Vancouver, ISO, and other styles
19

Davis, Brian D., Howard E. Bond, Michael H. Siegel, and Robin Ciardullo. "A Census of Above-horizontal-branch Stars in Galactic Globular Clusters*." Astrophysical Journal 926, no. 1 (2022): 99. http://dx.doi.org/10.3847/1538-4357/ac4224.

Full text
Abstract:
Abstract We have carried out a search for above-horizontal-branch (AHB) stars—objects lying above the horizontal branch (HB) and blueward of the asymptotic giant branch (AGB) in the color–magnitude diagram—in 97 Galactic and seven Magellanic Cloud globular clusters (GCs). We selected AHB candidates based on photometry in the uBVI system, which is optimized for detection of low-surface-gravity stars with large Balmer jumps, in the color range −0.05 ≤ (B − V)0 ≤1.0. We then used Gaia astrometry and Gaussian-mixture modeling to confirm cluster membership and remove field interlopers. Our final ca
APA, Harvard, Vancouver, ISO, and other styles
20

Johnson, Christian I., Robert Michael Rich, Michael D. Young, et al. "Blanco DECam Bulge Survey (BDBS) II: project performance, data analysis, and early science results." Monthly Notices of the Royal Astronomical Society 499, no. 2 (2020): 2357–79. http://dx.doi.org/10.1093/mnras/staa2393.

Full text
Abstract:
ABSTRACT The Blanco DECam Bulge Survey (BDBS) imaged more than 200 sq deg of the Southern Galactic bulge using the ugrizY filters of the Dark Energy Camera, and produced point spread function photometry of approximately 250 million unique sources. In this paper, we present details regarding the construction and collation of survey catalogues, and also discuss the adopted calibration and dereddening procedures. Early science results are presented with a particular emphasis on the bulge metallicity distribution function and globular clusters. A key result is the strong correlation (σ ∼ 0.2 dex)
APA, Harvard, Vancouver, ISO, and other styles
21

Bailer-Jones, Coryn A. L., Morgan Fouesneau, and Rene Andrae. "Quasar and galaxy classification in Gaia Data Release 2." Monthly Notices of the Royal Astronomical Society 490, no. 4 (2019): 5615–33. http://dx.doi.org/10.1093/mnras/stz2947.

Full text
Abstract:
ABSTRACT We construct a supervised classifier based on Gaussian Mixture Models to probabilistically classify objects in Gaia data release 2 (GDR2) using only photometric and astrometric data in that release. The model is trained empirically to classify objects into three classes – star, quasar, galaxy – for G ≥ 14.5 mag down to the Gaia magnitude limit of G = 21.0 mag. Galaxies and quasars are identified for the training set by a cross-match to objects with spectroscopic classifications from the Sloan Digital Sky Survey. Stars are defined directly from GDR2. When allowing for the expectation t
APA, Harvard, Vancouver, ISO, and other styles
22

Black, William K., and August E. Evrard. "Cosmic Dragons: A Two-Component Mixture Model of COSMOS Galaxies." Open Journal of Astrophysics 7 (April 4, 2024). http://dx.doi.org/10.33232/001c.116171.

Full text
Abstract:
Using the photometric population prediction method {}, we characterize the Red Sequence (RS) and Blue Cloud (BC) of DES galaxies in the COSMOS field. Red Dragon (RD) uses a redshift-evolving, error-corrected Gaussian mixture model to detail the distribution of photometric colors, smoothly parameterizing the two populations with relative weights, mean colors, intrinsic scatters, and inter-color correlations. This resulting fit of RS and BC yields RS membership probabilities for each galaxy. Even when training on only DES main bands griz, RD selects the quiescent population (defined here as gala
APA, Harvard, Vancouver, ISO, and other styles
23

Rodrigo, Carlos, Patricia Cruz, John F. Aguilar, et al. "Photometric segregation of dwarf and giant FGK stars using the SVO Filter Profile Service and photometric tools." Astronomy & Astrophysics, June 10, 2024. http://dx.doi.org/10.1051/0004-6361/202449998.

Full text
Abstract:
This paper is focused on the segregation of FGK dwarf and giant stars through narrow-band photometric data using the Spanish Virtual Observatory (SVO) Filter Profile Service and associated photometric tools. We selected spectra from the MILES, STELIB, and ELODIE stellar libraries, and used SVO photometric tools to derive the synthetic photometry in 15 J-PAS narrow filters, which were especially selected to cover spectral features sensitive to gravity changes. Using machine-learning techniques as the Gaussian mixture model and the support vector machine, we defined several criteria based on J-P
APA, Harvard, Vancouver, ISO, and other styles
24

Liu, Wei, Yude Bu, Xiaoming Kong, Zhenping Yi, and Meng Liu. "Identifying hot subdwarf stars from photometric data using a Gaussian mixture model and graph neural network." Publications of the Astronomical Society of Japan, April 9, 2024. http://dx.doi.org/10.1093/pasj/psae013.

Full text
Abstract:
Abstract Hot subdwarf stars are very important for understanding stellar evolution, stellar astrophysics, and binary star systems. Identifying more such stars can help us better understand their statistical distribution, properties, and evolution. In this paper, we present a new method to search for hot subdwarf stars in photometric data (BP, RP, G, g, r, i, z, y) using a machine-learning algorithm, a graph neural network, and a Gaussian mixture model. We use a Gaussian mixture model and Markov distance to build the graph structure, and on the graph structure we use a graph neural network to i
APA, Harvard, Vancouver, ISO, and other styles
25

Roster, William, M. Salvato, S. Krippendorf, et al. "PICZL : Image-based photometric redshifts for AGN." Astronomy & Astrophysics, November 14, 2024. http://dx.doi.org/10.1051/0004-6361/202452361.

Full text
Abstract:
Computing reliable photometric redshifts (photo-z) for active galactic nuclei (AGN) is a challenging task, primarily due to the complex interplay between the unresolved relative emissions associated with the supermassive black hole and its host galaxy. Spectral energy distribution (SED) fitting methods, while effective for galaxies and AGN in pencil-beam surveys, face limitations in wide or all-sky surveys with fewer bands available, lacking the ability to accurately capture the AGN contribution to the SED, hindering reliable redshift estimation. This limitation is affecting the many tens of m
APA, Harvard, Vancouver, ISO, and other styles
26

Garcia, Jonathan Cabrera, Timothy C. Beers, Yang Huang, et al. "Probing the Galactic halo with RR Lyrae stars – V. Chemistry, kinematics, and dynamically tagged groups." Monthly Notices of the Royal Astronomical Society, December 5, 2023. http://dx.doi.org/10.1093/mnras/stad3674.

Full text
Abstract:
Abstract We employ a sample of 135,873 RR Lyrae stars (RRLs) with precise photometric-metallicity and distance estimates from the newly calibrated P–φ31–R21–[Fe/H] and Gaia G-band P–R21–[Fe/H] absolute magnitude-metallicity relations of Li et al., combined with available proper motions from Gaia EDR3, and 6955 systemic radial velocities from Gaia DR3 and other sources, in order to explore the chemistry and kinematics of the halo of the Milky Way (MW). This sample is ideally suited for characterization of the inner- and outer-halo populations of the stellar halo, free from the bias associated w
APA, Harvard, Vancouver, ISO, and other styles
27

Biswas, Samrat, Biman J. Medhi, Sushmita Deb, Sukanta Deb, H. S. Das, and G. I. Perren. "A statistical approach to polarimetric and photometric investigation of the intermediate-age open cluster NGC 1912." Monthly Notices of the Royal Astronomical Society, June 12, 2024. http://dx.doi.org/10.1093/mnras/stae1476.

Full text
Abstract:
Abstract This paper presents a comprehensive multi-wavelength investigation of the intermediate-age open cluster NGC 1912. We identified 401 member stars for NGC 1912 using K-nearest neighbour (kNN) and Gaussian Mixture Model (GMM) machine learning techniques. The fundamental parameters determined for the cluster are Metallicity (z) = 0.0141 ± 0.0006, Log(age) = 8.519 ± 0.040, Binary fraction (bfrac) = 0.445 ± 0.035, Visual extinction (AV) = 0.864 ± 0.033 mag, Total-to-selective extinction ratio (RV) = 3.007 ± 0.096, distance = 1096 ± 15 pc. The central density (ρo), core radius (rc), tidal
APA, Harvard, Vancouver, ISO, and other styles
28

Ramírez, K. Peña, L. C. Smith, S. Ramírez Alegría, et al. "The VVV open cluster project II. Near-infrared sequences of 37 open clusters on eight-dimensional parameter space." Monthly Notices of the Royal Astronomical Society, May 11, 2022. http://dx.doi.org/10.1093/mnras/stac1296.

Full text
Abstract:
Abstract Open clusters are key coeval structures that help us understand star formation stellar evolution and trace the physical properties of our Galaxy. In the past years, the isolation of open clusters from the field has been heavily alleviated by the access to accurate large-scale stellar parallaxes and proper motions along a determined line of sight. Still, there are limitations regarding their completeness since large-scale studies rely on optical wavelengths. Here we extend the open clusters sequences towards fainter magnitudes complementing the Gaia photometric and astrometric informat
APA, Harvard, Vancouver, ISO, and other styles
29

Fraser, T. S., R. Tojeiro, and H. G. Chittenden. "Applying unsupervised learning to resolve evolutionary histories and explore the galaxy-halo connection in IllustrisTNG." Monthly Notices of the Royal Astronomical Society, January 11, 2023. http://dx.doi.org/10.1093/mnras/stad015.

Full text
Abstract:
Abstract We examine the effectiveness of identifying distinct evolutionary histories in IllustrisTNG-100 galaxies using unsupervised machine learning with Gaussian Mixture Models. We focus on how clustering compressed metallicity histories and star formation histories produces subpopulations of galaxies with distinct evolutionary properties (for both halo mass assembly and merger histories). By contrast, clustering with photometric colours fail to resolve such histories. We identify several populations of interest that reflect a variety of evolutionary scenarios supported by the literature. No
APA, Harvard, Vancouver, ISO, and other styles
30

Nanni, Riccardo, Joseph F. Hennawi, Feige Wang, Jinyi Yang, Jan-Torge Schindler, and Xiaohui Fan. "Paving the way for euclid and JWST via probabilistic selection of high-redshift quasars." Monthly Notices of the Royal Astronomical Society, July 23, 2022. http://dx.doi.org/10.1093/mnras/stac1944.

Full text
Abstract:
Abstract We introduce a probabilistic approach to select 6 ≤ z ≤ 8 quasar candidates for spectroscopic follow-up, which is based on density estimation in the high-dimensional space inhabited by the optical and near-infrared photometry. Densities are modeled as Gaussian mixtures with principled accounting of errors using the extreme deconvolution (XD) technique, generalizing an approach successfully used to select lower redshift (z ≤ 3) quasars. We train the probability density of contaminants on 1,902,071 7-d flux measurements from the 1076 deg2 overlapping area from the DECaLS (z), VIKING (YJ
APA, Harvard, Vancouver, ISO, and other styles
31

Nogueras-Lara, F., N. Nieuwmunster, M. Schultheis, et al. "Metallicity-dependent kinematics and orbits in the Milky Way's nuclear stellar disc." Astronomy & Astrophysics, September 23, 2024. http://dx.doi.org/10.1051/0004-6361/202450946.

Full text
Abstract:
The nuclear stellar disc (NSD) is a flat and dense stellar structure at the centre of the Milky Way. Previous work has identified the presence of metal-rich and metal-poor stars in the NSD, suggesting that they have different origins. The recent publication of photometric, metallicity, proper motion, and orbital catalogues allows the NSD stellar population to be characterised with unprecedented detail. We aim to explore the proper motions and orbits of NSD stars with different metallicities to assess whether they have different origins and to better understand the metallicity distribution in t
APA, Harvard, Vancouver, ISO, and other styles
32

Ortega-Martinez, Sara, Aura Obreja, Rosa Dominguez-Tenreiro, Susana E. Pedrosa, Yetli Rosas-Guevara, and Patricia B. Tissera. "Milky Way-like galaxies: Stellar population properties of dynamically defined disks, bulges and stellar haloes." Monthly Notices of the Royal Astronomical Society, July 23, 2022. http://dx.doi.org/10.1093/mnras/stac2033.

Full text
Abstract:
Abstract The formation of galaxies can be understood in terms of the assembly patterns of each type of galactic component. To perform this kind of analysis, is necessary to define some criteria to separate those components. Decomposition methods based on dynamical properties are more physically motivated than photometry-based ones. We use the unsupervised Gaussian Mixture model of galactic structure finder to extract the components of a sub-sample of galaxies with Milky Way-like masses from the EAGLE simulations. A clustering in the space of first and second order dynamical moments of all iden
APA, Harvard, Vancouver, ISO, and other styles
33

Fukushima, Tetsuya, Masashi Chiba, Mikito Tanaka, et al. "The stellar halo of the Milky Way traced by blue horizontal-branch stars in the Subaru Hyper Suprime-Cam Survey." Publications of the Astronomical Society of Japan 71, no. 4 (2019). http://dx.doi.org/10.1093/pasj/psz052.

Full text
Abstract:
Abstract We report on the global structure of the Milky Way (MW) stellar halo up to its outer boundary based on the analysis of blue horizontal-branch stars (BHBs). These halo tracers are extracted from the (g, r, i, z)-band multi-photometry in the internal data release of the ongoing Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) surveyed over a ∼550 deg2 area. In order to select the most likely BHBs by removing blue straggler stars (BSs) and other contamination in a statistically significant manner, we have developed and applied an extensive Bayesian method, instead of the simple color
APA, Harvard, Vancouver, ISO, and other styles
34

Ruppin, F., M. Rigault, M. Ginolin, et al. "ZTF SN Ia DR2: Impact of the galaxy cluster environment on the stretch distribution of Type Ia supernovae." Astronomy & Astrophysics, October 3, 2024. http://dx.doi.org/10.1051/0004-6361/202450956.

Full text
Abstract:
Understanding the impact of the astrophysical environment on Type Ia supernova (SN Ia) properties is crucial to minimize systematic uncertainties in cosmological analyses based on this probe. We investigate the dependence of the SN Ia SALT2.4 light-curve stretch on the distance from their nearest galaxy cluster to study the potential effect of the intracluster medium (ICM) environment on the intrinsic properties of SN Ia. We used the largest SN Ia sample to date and cross-matched it with existing X-ray, Sunyaev-Zel'dovich, and optical cluster catalogs in order to study the relation between the
APA, Harvard, Vancouver, ISO, and other styles
35

sprotocols. "Imaging and Analysis of OT1 T Cell Activation on Lipid Bilayers." January 7, 2015. https://doi.org/10.5281/zenodo.13784.

Full text
Abstract:
Authors: Peter Beemiller, Jordan Jacobelli & Matthew Krummel ### Abstract Supported lipid bilayers are frequently used to study cell membrane protein dynamics during immune synapse formation by T cells. Here we describe methods for the imaging and analysis of OT1+ T cell activation and T-cell receptor (TCR) dynamics on lipid bilayers. ### Introduction T cells are activated at immune synapses when TCRs bind agonist ligands on antigen presenting cells (APCs). Glass coverslip–supported lipid bilayers provide a system for in vitro T cell activation and immune synapse formation. In these system
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography