Search Publications

Application of the Deep Convolutional Neural Network to the Forecast of Solar Flare Occurrence Using Full-disk Solar Magnetograms
DOI: 10.3847/1538-4357/aaed40 Bibcode: 2018ApJ...869...91P

Moon, Yong-Jae; Lim, Daye; Lee, Harim +4 more

In this study, we present the application of the Convolutional Neural Network (CNN) to the forecast of solar flare occurrence. For this, we consider three CNN models (two pretrained models, AlexNet and GoogLeNet, and one newly proposed model). Our inputs are SOHO/Michelson Doppler Imager (from 1996 May to 2010 December) and SDO/Helioseismic and Ma…

2018 The Astrophysical Journal
SOHO 66
ALMA Observations of Molecular Clouds in Three Group-centered Elliptical Galaxies: NGC 5846, NGC 4636, and NGC 5044
DOI: 10.3847/1538-4357/aab9b0 Bibcode: 2018ApJ...858...17T

Brighenti, Fabrizio; Mathews, William G.; Temi, Pasquale +4 more

We present new ALMA CO(2-1) observations of two well-studied group-centered elliptical galaxies: NGC 4636 and NGC 5846. In addition, we include a revised analysis of Cycle 0 ALMA observations of the central galaxy in the NGC 5044 group. We find evidence that molecular gas is a common presence in bright group-centered galaxies (BGG). CO line widths…

2018 The Astrophysical Journal
eHST 66
A Submillimeter Perspective on the GOODS Fields (SUPER GOODS). III. A Large Sample of ALMA Sources in the GOODS-S
DOI: 10.3847/1538-4357/aadc63 Bibcode: 2018ApJ...865..106C

Bauer, F. E.; Wang, W. -H.; Barger, A. J. +3 more

We analyze the >4σ sources in the most sensitive 100 arcmin2 area (rms < 0.56 mJy) of a SCUBA-2 850 µm survey of the GOODS-S and present the 75 band-7 ALMA sources (>4.5σ) obtained from high-resolution interferometric follow-up observations. The raw SCUBA-2 >4σ limit is fainter than 2.25 mJy throughout this region, and…

2018 The Astrophysical Journal
eHST 66
Investigating the Response of Loop Plasma to Nanoflare Heating Using RADYN Simulations
DOI: 10.3847/1538-4357/aab49e Bibcode: 2018ApJ...856..178P

Reale, Fabio; De Pontieu, B.; Carlsson, M. +5 more

We present the results of 1D hydrodynamic simulations of coronal loops that are subject to nanoflares, caused by either in situ thermal heating or nonthermal electron (NTE) beams. The synthesized intensity and Doppler shifts can be directly compared with Interface Region Imaging Spectrograph (IRIS) and Atmospheric Imaging Assembly (AIA) observatio…

2018 The Astrophysical Journal
IRIS 66
Gaia and the Galactic Center Origin of Hypervelocity Stars
DOI: 10.3847/1538-4357/aadb8e Bibcode: 2018ApJ...866...39B

Geller, Margaret J.; Brown, Warren R.; Kenyon, Scott J. +1 more

We use new Gaia measurements to explore the origin of the highest velocity stars in the hypervelocity star (HVS) survey. The measurements reveal a clear pattern in B-type stars. Halo stars dominate the sample at speeds of ≃100 km s-1 below Galactic escape velocity. Disk runaway stars have speeds up to ≃100 km s-1 above Galact…

2018 The Astrophysical Journal
Gaia eHST 66
LensFlow: A Convolutional Neural Network in Search of Strong Gravitational Lenses
DOI: 10.3847/1538-4357/aaae6a Bibcode: 2018ApJ...856...68P

Cooray, Asantha; Nayyeri, Hooshang; Pourrahmani, Milad

In this work, we present our machine learning classification algorithm for identifying strong gravitational lenses from wide-area surveys using convolutional neural networks; LENSFLOW. We train and test the algorithm using a wide variety of strong gravitational lens configurations from simulations of lensing events. Images are processed through mu…

2018 The Astrophysical Journal
eHST 65
Detection of Reflection Features in the Neutron Star Low-mass X-Ray Binary Serpens X-1 with NICER
DOI: 10.3847/2041-8213/aabee6 Bibcode: 2018ApJ...858L...5L

Fabian, A. C.; Miller, J. M.; Homan, J. +17 more

We present Neutron Star Interior Composition Explorer (NICER) observations of the neutron star (NS) low-mass X-ray binary Serpens X-1 during the early mission phase in 2017. With the high spectral sensitivity and low-energy X-ray passband of NICER, we are able to detect the Fe L line complex in addition to the signature broad, asymmetric Fe K line…

2018 The Astrophysical Journal
XMM-Newton 65
Results from a Systematic Survey of X-Ray Emission from Hydrogen-poor Superluminous SNe
DOI: 10.3847/1538-4357/aad2df Bibcode: 2018ApJ...864...45M

Berger, E.; Chornock, R.; Lunnan, R. +11 more

We present the results from a sensitive X-ray survey of 26 nearby hydrogen-poor superluminous supernovae (SLSNe-I) with Swift, Chandra, and XMM. This data set constrains the SLSN evolution from a few days until ∼2000 days after explosion, reaching a luminosity limit L x ∼ 1040 erg s-1 and revealing the presence o…

2018 The Astrophysical Journal
XMM-Newton 65
RELICS: Strong Lens Models for Five Galaxy Clusters from the Reionization Lensing Cluster Survey
DOI: 10.3847/1538-4357/aabe7b Bibcode: 2018ApJ...859..159C

Frye, Brenda L.; Bradač, Maruša; Lovisari, Lorenzo +31 more

Strong gravitational lensing by galaxy clusters magnifies background galaxies, enhancing our ability to discover statistically significant samples of galaxies at {\boldsymbol{z}}> 6, in order to constrain the high-redshift galaxy luminosity functions. Here, we present the first five lens models out of the Reionization Lensing Cluster Survey (RE…

2018 The Astrophysical Journal
eHST 65
Identifying Typical Mg II Flare Spectra Using Machine Learning
DOI: 10.3847/1538-4357/aac779 Bibcode: 2018ApJ...861...62P

Krucker, Säm; Kleint, Lucia; Panos, Brandon +4 more

The Interface Region Imaging Spectrograph (IRIS) performs solar observations over a large range of atmospheric heights, including the chromosphere where the majority of flare energy is dissipated. The strong Mg II h&k spectral lines are capable of providing excellent atmospheric diagnostics, but have not been fully utilized for flaring atmosph…

2018 The Astrophysical Journal
IRIS 65