Cheap balloon-borne telescopes aim to rival space observatories

Science ◽  
2020 ◽  
Author(s):  
Adrian Cho
Keyword(s):  
Space Observatories

scholarly journals Substellar and low-mass dwarf identification with near-infrared imaging space observatories

2018 ◽  
Vol 620 ◽  
pp. A132 ◽  
Author(s):  
B. W. Holwerda ◽  
J. S. Bridge ◽  
R. Ryan ◽  
M. A. Kenworthy ◽  
N. Pirzkal ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Imaging ◽  
High Redshift ◽  
Brown Dwarfs ◽  
Wide Field ◽  
Space Telescope ◽  
Low Mass ◽  
Space Observatories ◽  
Broad Type ◽  
Selection Of

Aims. We aim to evaluate the near-infrared colors of brown dwarfs as observed with four major infrared imaging space observatories: the Hubble Space Telescope (HST), the James Webb Space Telescope (JWST), the Euclid mission, and the WFIRST telescope. Methods. We used the SPLAT SPEX/ISPEX spectroscopic library to map out the colors of the M-, L-, and T-type dwarfs. We have identified which color–color combination is optimal for identifying broad type and which single color is optimal to then identify the subtype (e.g., T0-9). We evaluated each observatory separately as well as the narrow-field (HST and JWST) and wide-field (Euclid and WFIRST) combinations. Results. The Euclid filters perform equally well as HST wide filters in discriminating between broad types of brown dwarfs. WFIRST performs similarly well, despite a wider selection of filters. However, subtyping with any combination of Euclid and WFIRST observations remains uncertain due to the lack of medium, or narrow-band filters. We argue that a medium band added to the WFIRST filter selection would greatly improve its ability to preselect brown dwarfs its imaging surveys. Conclusions. The HST filters used in high-redshift searches are close to optimal to identify broad stellar type. However, the addition of F127M to the commonly used broad filter sets would allow for unambiguous subtyping. An improvement over HST is one of two broad and medium filter combinations on JWST: pairing F140M with either F150W or F162M discriminates very well between subtypes.

Observability of YSOs with the WISE and AKARI infrared space observatories

2013 ◽  
Vol 334 (9) ◽  
pp. 928-931
Author(s):  
S. Zahorecz ◽  
L.V. Töth ◽  
G. Marton ◽  
M. Ueno ◽  
M. Tamura ◽  
...  
Keyword(s):  
Space Observatories

scholarly journals Measuring the Microlensing Parallax from Various Space Observatories

2018 ◽  
Vol 155 (5) ◽  
pp. 191 ◽  
Author(s):  
E. Bachelet ◽  
T. C. Hinse ◽  
R. Street
Keyword(s):  
Space Observatories

scholarly journals Innovative telescope architectures for future large space observatories

2016 ◽  
Vol 2 (4) ◽  
pp. 041211 ◽  
Author(s):  
Ronald S. Polidan ◽  
James B. Breckinridge ◽  
Charles F. Lillie ◽  
Howard A. MacEwen ◽  
Martin R. Flannery ◽  
...  
Keyword(s):  
Large Space ◽  
Space Observatories

scholarly journals Studying the Galactic Central Engine from Space Observatories

1990 ◽  
Vol 123 ◽  
pp. 559-561
Author(s):  
Howard D. Greyber
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Field Configuration ◽  
Energy Output ◽  
Current Loop ◽  
Central Engine ◽  
Dipole Magnetic Field ◽  
The Galaxy ◽  
Magnetic Field Model ◽  
Space Observatories

Three general models have been constructed for the fantastically powerful “central engine” that powers the enormous energy output from quasars and active galactic nuclei (AGN). One model assumes a rapidly rotating accretion disk around a central black hole (however the disks, thick or thin, are subject to violent instabilities). Another assumes that in some postulated circuitry energy is extracted from the rotational portion of the deepest potential hole known, a black hole. Both models appear implausible.The third model is the STRONG MAGNETIC FIELD MODEL (SMF) in which an extremely strong gravitationally bound current loop (GBCL) is formed during the gravitational collapse that forms the galaxy or quasar, producing a very intense dipole magnetic field anchored in the nucleus. SMF, first published in 1962, thus predicted the vertical magnetic field configuration seen today at our own galactic nucleus; to some the radio arcs observed suggest a dipole magnetic field there, just as SMF predicts.

scholarly journals The Eccentric and Accelerating Stellar Binary Black Hole Mergers in Galactic Nuclei: Observing in Ground and Space Gravitational-wave Observatories

2021 ◽  
Vol 923 (2) ◽  
pp. 139
Author(s):  
Fupeng Zhang ◽  
Xian Chen ◽  
Lijing Shao ◽  
Kohei Inayoshi
Keyword(s):  
Black Hole ◽  
Gravitational Wave ◽  
Signal To Noise Ratio ◽  
Galactic Nuclei ◽  
Signal To Noise ◽  
High Eccentricity ◽  
Massive Black Hole ◽  
Binary Black Holes ◽  
Binary Black Hole ◽  
Space Observatories

Abstract We study the stellar binary black holes (BBHs) inspiraling/merging in galactic nuclei based on our numerical method GNC. We find that 3%–40% of all newborn BBHs will finally merge due to various dynamical effects. In a five-year mission, up to 104, 105, and ∼100 of BBHs inspiraling/merging in galactic nuclei can be detected with signal-to-noise ration >8 in Advanced LIGO (aLIGO), Einstein/DECIGO, and TianQin/LISA/TaiJi, respectively. Roughly tens are detectable in both LISA/TaiJi/TianQin and aLIGO. These BBHs have two unique characteristics. (1) Significant eccentricities: 1%–3%, 2%–7%, or 30%–90% of them have e i > 0.1 when they enter into aLIGO, Einstein, or space observatories, respectively. Such high eccentricities provide a possible explanation for that of GW190521. Most highly eccentric BBHs are not detectable in LISA/Tianqin/TaiJi before entering into aLIGO/Einstein, as their strain becomes significant only at f GW ≳ 0.1 Hz. DECIGO becomes an ideal observatory to detect those events, as it can fully cover the rising phase. (2) Up to 2% of BBHs can inspiral/merge at distances ≲103 r SW from the massive black hole, with significant accelerations, such that the Doppler phase drift of ∼10–105 of them can be detected with signal-to-noise ratio >8 in space observatories. The energy density of the gravitational-wave backgrounds (GWBs) contributed by these BBHs deviates from the power-law slope of 2/3 at f GW ≲ 1 mHz. The high eccentricity, significant accelerations, and the different profile of the GWB of these sources make them distinguishable, and thus interesting for future gravitational-wave detections and tests of relativities.

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