scholarly journals Accretion phenomena in nearby star-forming dwarf galaxies

2016 ◽  
Vol 11 (S321) ◽  
pp. 211-213
Author(s):  
F. Annibali ◽  
M. Tosi ◽  
A. Aloisi ◽  
M. Bellazzini ◽  
A. Buzzoni ◽  
...  
Keyword(s):  
Dwarf Galaxies ◽  
Chemical Properties ◽  
Direct Search ◽  
Wide Field ◽  
Nearby Star ◽  
Pilot Studies ◽  
Star Forming ◽  
Field Imaging ◽  
Wide Field Imaging

AbstractWe present two pilot studies for the search and characterization of accretion events in star-forming dwarf galaxies. Our strategy consists of two complementary approaches: i) the direct search for stellar substructures around dwarf galaxies through deep wide-field imaging, and ii) the characterization of the chemical properties in these systems up to large galacto-centric distances. We show our results for two star-forming dwarf galaxies, the starburst irregular NGC 4449, and the extremely metal-poor dwarf DDO 68.

scholarly journals VLA imaging of the XMM-LSS/VIDEO deep field at 1–2 GHz

2020 ◽  
Vol 496 (3) ◽  
pp. 3469-3481
Author(s):  
I Heywood ◽  
C L Hale ◽  
M J Jarvis ◽  
S Makhathini ◽  
J A Peters ◽  
...  
Keyword(s):  
Angular Resolution ◽  
Cosmic Time ◽  
Wide Field ◽  
Radio Telescopes ◽  
Very Large Array ◽  
Star Forming ◽  
Normal Star ◽  
Average Spectrum ◽  
Field Imaging ◽  
Wide Field Imaging

ABSTRACT Modern radio telescopes are routinely reaching depths where normal star-forming galaxies are the dominant observed population. Realizing the potential of radio as a tracer of star formation and black hole activity over cosmic time involves achieving such depths over representative volumes, with radio forming part of a larger multiwavelength campaign. In pursuit of this, we used the Karl G. Jansky Very Large Array (VLA) to image ∼5 deg2 of the VIDEO/XMM-LSS extragalactic deep field at 1–2 GHz. We achieve a median depth of 16 µJy beam−1 with an angular resolution of 4.5 arcsec. Comparisons with existing radio observations of XMM-LSS showcase the improved survey speed of the upgraded VLA: we cover 2.5 times the area and increase the depth by ∼20 per cent in 40 per cent of the time. Direction-dependent calibration and wide-field imaging were required to suppress the error patterns from off-axis sources of even modest brightness. We derive a catalogue containing 5762 sources from the final mosaic. Sub-band imaging provides in-band spectral indices for 3458 (60 per cent) sources, with the average spectrum becoming flatter than the canonical synchrotron slope below 1 mJy. Positional and flux density accuracy of the observations, and the differential source counts are in excellent agreement with those of existing measurements. A public release of the images and catalogue accompanies this article.

scholarly journals Fabrication and Characterization of Curved Compound Eyes Based on Multifocal Microlenses

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 854 ◽  
Author(s):  
Gaoge Lian ◽  
Yongshun Liu ◽  
KeKai Tao ◽  
Huaming Xing ◽  
Ruxia Huang ◽  
...  
Keyword(s):  
Compound Eye ◽  
Accurate Method ◽  
Field Of View ◽  
Curved Surface ◽  
Compound Eyes ◽  
Wide Field ◽  
Wide Field Of View ◽  
Field Imaging ◽  
Wide Field Imaging

Curved compound eyes have generated great interest owing to the wide field of view but the application of devices is hindered for the lack of proper detectors. One-lens curved compound eyes with multi-focal microlenses provide a solution for wide field imaging integrated in a commercial photo-detector. However, it is still a challenge for manufacturing this kind of compound eye. In this paper, a rapid and accurate method is proposed by a combination of photolithography, hot embossing, soft photolithography, and gas-assisted deformation techniques. Microlens arrays with different focal lengths were firstly obtained on a polymer, and then the planar structure was converted to the curved surface. A total of 581 compound eyes with diameters ranging from 152.8 µm to 240.9 µm were successfully obtained on one curved surface within a few hours, and the field of view of the compound eyes exceeded 108°. To verify the characteristics of the fabricated compound eyes, morphology deviation was measured by a probe profile and a scanning electron microscope. The optical performance and imaging capability were also tested and analyzed. As a result, the ommatidia made up of microlenses showed not only high accuracy in morphology, but also imaging uniformity on a focal plane. This flexible massive fabrication of compound eyes indicates great potential for miniaturized imaging systems.

scholarly journals Design and characterization of a combined OCT and wide field imaging falloposcope for ovarian cancer detection

2016 ◽  
Vol 8 (1) ◽  
pp. 124 ◽  
Author(s):  
Molly Keenan ◽  
Tyler H. Tate ◽  
Khanh Kieu ◽  
John F. Black ◽  
Urs Utzinger ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Detection ◽  
Wide Field ◽  
Field Imaging ◽  
Wide Field Imaging

scholarly journals The Brown Dwarf Deficit in Taurus: Evidence for a Non-Universal IMF

2003 ◽  
Vol 211 ◽  
pp. 81-82 ◽  
Author(s):  
César Briceño ◽  
Kevin L. Luhman ◽  
Lee Hartmann ◽  
John R. Stauffer ◽  
J. Davy Kirkpatrick
Keyword(s):  
Brown Dwarfs ◽  
Mass Function ◽  
Initial Mass Function ◽  
Wide Field ◽  
Low Density ◽  
Brown Dwarf ◽  
New Members ◽  
Star Forming ◽  
Field Imaging ◽  
Wide Field Imaging

We present the results of a deep, optical/IR wide field imaging survey of selected fields in the nearby (d~ 140 pc) Taurus star-forming region. We report the discovery of 9 new members with spectral types M5.75–M9.5. We derive an Initial Mass Function encompassing 54% of the known members in Taurus. Comparison with dense regions like the Trapezium Cluster in Orion shows that Taurus has produced x2 less brown dwarfs. We suggest that the lower frequency of brown dwarfs in Taurus may result from the low-density star-forming environment, leading to larger minimum Jeans masses.

scholarly journals Camera-based localization microscopy optimized with calibrated structured illumination

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Martin Schmidt ◽  
Adam C. Hundahl ◽  
Henrik Flyvbjerg ◽  
Rodolphe Marie ◽  
Kim I. Mortensen
Keyword(s):  
Data Analysis ◽  
Super Resolution ◽  
Wide Field ◽  
Structured Illumination ◽  
Uniform Illumination ◽  
Localization Microscopy ◽  
Localization And Tracking ◽  
Field Imaging ◽  
Wide Field Imaging ◽  
Localization Information

AbstractUntil very recently, super-resolution localization and tracking of fluorescent particles used camera-based wide-field imaging with uniform illumination. Then it was demonstrated that structured illuminations encode additional localization information in images. The first demonstration of this uses scanning and hence suffers from limited throughput. This limitation was mitigated by fusing camera-based localization with wide-field structured illumination. Current implementations, however, use effectively only half the localization information that they encode in images. Here we demonstrate how all of this information may be exploited by careful calibration of the structured illumination. Our approach achieves maximal resolution for given structured illumination, has a simple data analysis, and applies to any structured illumination in principle. We demonstrate this with an only slightly modified wide-field microscope. Our protocol should boost the emerging field of high-precision localization with structured illumination.

scholarly journals Protocol for constructing an extensive cranial window utilizing a PEO-CYTOP nanosheet for in vivo wide-field imaging of the mouse brain

2021 ◽  
Vol 2 (2) ◽  
pp. 100542
Author(s):  
Taiga Takahashi ◽  
Hong Zhang ◽  
Kohei Otomo ◽  
Yosuke Okamura ◽  
Tomomi Nemoto
Keyword(s):  
Mouse Brain ◽  
Wide Field ◽  
Cranial Window ◽  
Field Imaging ◽  
Wide Field Imaging
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