Zobrazeno 1 - 10
of 17
pro vyhledávání: '"H. J. Hagenaar"'
Publikováno v:
The Astrophysical Journal. 720:1405-1416
Understanding the behavior of weak magnetic fields near the detection limit of current instrumentation is important for determining the flux budget of the solar photosphere at small spatial scales. Using 0.''3-resolution magnetograms from the Solar O
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::1d90aa6963c899461860b74b14d117a8
https://doi.org/10.1088/0004-637x/720/2/1405
https://doi.org/10.1088/0004-637x/720/2/1405
Autor:
H. J. Hagenaar, Clare E. Parnell, Blair A. Johnston, Derek A. Lamb, Craig DeForest, Brian T. Welsch
Publikováno v:
The Astrophysical Journal. 698:75-82
Solar flares, coronal mass ejections, and indeed phenomena on all scales observed on the Sun, are inextricably linked with the Sun’s magnetic field. The solar surface is covered with magnetic features observed on many spatial scales, which evolve o
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::0a2563a99cf1f1aa7b895799c9c82e27
https://doi.org/10.1088/0004-637x/698/1/75
https://doi.org/10.1088/0004-637x/698/1/75
Publikováno v:
The Astrophysical Journal. 678:541-548
We investigate the distribution and evolution of existing and emerging magnetic network elements in the quiet-Sun photosphere. The ephemeral region emergence rate is found to depend primarily on the imbalance of magnetic flux in the area surrounding
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::00008b86b00667cdf095401911e87839
https://doi.org/10.1086/533497
https://doi.org/10.1086/533497
Publikováno v:
The Astrophysical Journal. 674:520-529
We investigate the origin of small-scale flux concentrations in the quiet Sun. In apparent violation of the physical requirement for flux balance, 94% of the features containing newly detected flux are unipolar at a resolution of 1.2''. We analyze 26
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::a967159bfffc9bb937f37144d263218e
https://doi.org/10.1086/524372
https://doi.org/10.1086/524372
Publikováno v:
The Astrophysical Journal. 671:L85-L88
We present novel evidence for a fine structure observed in the net-circular polarization (NCP) of a sunspot penumbra based on spectropolarimetric measurements utilizing the Zeeman sensitive FeI 630.2 nm line. For the first time we detect a filamentar
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::660a60c0eacd938593ef1577c29cfa0f
https://doi.org/10.1086/524872
https://doi.org/10.1086/524872
In this second paper in the series, we investigate occurrence frequencies of apparent unipolar processes, cancellation, and emergence of patch structures in quiet regions. Apparent unipolar events are considerably more frequent than cancellation and
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4c3c443c8a3b22a8887c046dd804bdb3
Autor:
Richard A. Shine, H. J. Hagenaar
Publikováno v:
The Astrophysical Journal. 635:659-669
We study statistical properties of small-scale magnetic features around sunspots using time sequences of high-resolution magnetograms of eight sunspots made with the Michelson Doppler Imager (MDI) on board SOHO. Flow maps around the spots are also de
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::edd22e77221c44231995ba8862e72e79
https://doi.org/10.1086/497367
https://doi.org/10.1086/497367
Publikováno v:
The Astrophysical Journal. 584:1107-1119
We find that bipolar active regions that emerge onto the Sun's surface are part of a smoothly decreasing frequency distribution that spans almost 4 orders of magnitude in flux and 8 orders of magnitude in frequency. Distributions of emergence latitud
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::feacdc4f8d4c5050cf6a5b20cd09ca87
https://doi.org/10.1086/345792
https://doi.org/10.1086/345792
Autor:
H. J. Hagenaar
Publikováno v:
The Astrophysical Journal. 555:448-461
Ephemeral regions are small-scale, bipolar regions of magnetic field, emerging all over the solar surface. As structures ephemeral regions are short-lived; they can be recognized for 4.4 hr on average. This paper examines a 3.5 day sequence of full-d
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::4d9a636be332b5ea02d68fdf014dfde5
https://doi.org/10.1086/321448
https://doi.org/10.1086/321448
Publikováno v:
The Astrophysical Journal. 481:988-995
This paper studies the cellular pattern of the supergranular network. We present an algorithm to draw a surface-filling cell pattern on an uninterrupted two-day sequence of Ca II K filtergrams with a 1 nm bandpass. The 60° × 40° field of view cont
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::e82a0a05f2188a906cb673ca41fbe2d4
https://doi.org/10.1086/304066
https://doi.org/10.1086/304066