Integrated superconducting spectrometer (ISS) technology will enable ultra-wideband, integral-field spectroscopy for (sub)millimeter-wave astronomy, in particular, for uncovering the dust-obscured ...cosmic star formation and galaxy evolution over cosmic time. Here, we present the development of DESHIMA 2.0, an ISS for ultra-wideband spectroscopy toward high-redshift galaxies. DESHIMA 2.0 is designed to observe the 220–440 GHz band in a single shot, corresponding to a redshift range of
z
= 3.3–7.6 for the ionized carbon emission (C II 158
μ
m). The first-light experiment of DESHIMA 1.0, using the 332–377 GHz band, has shown an excellent agreement among the on-sky measurements, the laboratory measurements, and the design. As a successor to DESHIMA 1.0, we plan the commissioning and the scientific observation campaign of DESHIMA 2.0 on the ASTE 10-m telescope in 2023. Ongoing upgrades for the full octave-bandwidth system include the wideband 347-channel chip design and the wideband quasi-optical system. For efficient measurements, we also develop the observation strategy using the mechanical fast sky-position chopper and the sky-noise removal technique based on a novel data-scientific approach. In the paper, we show the recent status of the upgrades and the plans for the scientific observation campaign.
We report on the cryogenic properties of a low-contraction silicon–aluminum composite, namely Japan Fine Ceramics SA001, to use as a packaging structure for cryogenic silicon devices. SA001 is ...silicon–aluminum composite material (75% silicon by volume) and has a low thermal expansion coefficient (
∼
1/3 that of aluminum). The superconducting transition temperature of SA001 is measured to be 1.18 K, which is in agreement with that of pure aluminum and is thus available as a superconducting magnetic shield material. The residual resistivity of SA001 is 0.065 µΩm, which is considerably lower than equivalent silicon–aluminum composite material. The measured thermal contraction of SA001 immersed in liquid nitrogen is
L
293
K
-
L
77
K
L
293
K
=
0.12
%
, which is consistent with the expected rate obtained from the volume-weighted mean of the contractions of silicon and aluminum. The machinability of SA001 is also confirmed with a demonstrated fabrication of a conical feedhorn array, with a wall thickness of 100 µm. These properties are suitable for packaging applications for large-format superconducting detector devices.
Abstract We present emission maps ( 1 .′ 5 × 1 .′ 5 scale, corresponding to 0.18 pc) of the DCN ( J = 2 − 1) and DCO + ( J = 2 − 1) lines in the 2 mm band toward the Orion KL region obtained with the ...2 mm receiver system named B4R installed on the Large Millimeter Telescope. The DCN emission shows a peak at the Orion KL hot core position, whereas no DCO + emission has been detected there. The DCO + emission shows enhancement at the west side of the hot core, which is well shielded from the UV radiation from OB massive stars in the Trapezium cluster. We have derived the abundance ratio of DCN/DCO + at three representative positions where both species have been detected. The gas components with V LSR ≈ 7.5–8.7 km s −1 are associated with low abundance ratios of ∼4–6, whereas much higher abundance ratios (∼22–30) are derived for the gas components with V LSR ≈ 9.2–11.6 km s −1 . We have compared the observed abundance ratio to our chemical models and found that the observed differences in the DCN/DCO + abundance ratios are explained by different densities.
We present the results of a blind millimeter line emitter search using ALMA Band 6 data with a single-frequency tuning toward four gravitational lensing clusters (RXJ1347.5−1145, Abell S0592, MACS ...J0416.1−2403, and Abell 2744). We construct 3D signal-to-noise ratio (S/N) cubes with 60 and 100 MHz binning, and search for millimeter line emitters. We do not detect any line emitters with a peak S/N > 5, although we do find a line emitter candidate with a peak S/N 4.5. These results provide upper limits to the CO(3−2), CO(4−3), CO(5−4), and C ii luminosity functions at z 0.3, 0.7, 1.2, and 6, respectively. Because of the magnification effect of gravitational lensing clusters, the new data provide the first constraints on the CO and C ii luminosity functions at unprecedentedly low luminosity levels, i.e., down to 10−3 - 10−1 Mpc−3 dex−1 at K km s−1 pc2 and 10−3-10−2 Mpc−3 dex−1 at , respectively. Although the constraints to date are not yet stringent, we find that the evolution of the CO and C ii luminosity functions are broadly consistent with the predictions of semi-analytical models. This study demonstrates that the wide observations with a single-frequency tuning toward gravitational lensing clusters are promising for constraining the CO and C ii luminosity functions.
We established a design method for a Magic-T with a single-layer dielectric/metal structure suitable for both wideband and multi-element applications for millimeter and submillimeter wave imaging ...observations. The design method was applied to a Magic-T with a coupled-line, stubs, and single-stage impedance transformers in a frequency-scaled model (6–14 GHz) that is relatively easy to demonstrate through manufacturing and evaluation. The major problem is that using the conventional perfect matching condition for a coupled-line alone produces an impractically large width coplanar coupled-line (CPCL) to satisfy the desired bandwidth ratio. In our study, by removing this constraint and optimizing impedances utilizing a circuit simulator with high computation speed, we found a solution with a
∼
180 μm wide CPCL, which is approximately an order of magnitude smaller than the conventional analytical solution. Furthermore, considering the effect of transition discontinuities in the transmission lines, we optimized the line length and obtained a design solution with return loss < − 20 dB, amplitude imbalance < 0.1 dB, and phase imbalance < 0.5
∘
from 6.1 to 14.1 GHz.
The X-Ray Observatory Suzaku Mitsuda, Kazuhisa; Inoue, Hajime; Kelley, Richard L ...
Publications of the Astronomical Society of Japan,
01/2007, Letnik:
59, Številka:
sp1
Journal Article
Recenzirano
Odprti dostop
High-sensitivity wide-band X-ray spectroscopy is the key feature of the Suzaku X-ray observatory, launched on 2005 July 10. This paper summarizes the spacecraft, in-orbit performance, operations, and ...data processing that are related to observations. The scientific instruments, the high-throughput X-ray telescopes, X-ray CCD cameras, non-imaging hard X-ray detector are also described.
We have carried out wide-field (0.17 deg super(2)) and high-angular resolution (21".3 ~0.04 pc) observations in the CI line toward the Orion-A giant molecular cloud with the Atacama Submillimeter ...Telescope Experiment 10 m telescope in the On-The-Fly mode. The overall features of the CI emission are similar to those of the super(12)CO (J = 1-0) emission by Shimajiri et al. in 2011; the total intensity ratio of the CI to CO emission ranges from 0.05 to 0.2. The optical depth of the CI emission is found to be 0.1-0.75, suggesting optically thin emission. The column density of the CI emission is estimated to be (1.0-19) x 10 super(17) cm super(-2). These results are consistent with the results of the previous CI observations with a low-angular resolution of 2'.2. In the nearly edge-on photon-dominated regions (PDRs) and their candidates of the Orion Bar, DLSF, M 43 Shell, and Region D, the distributions of the CI emission coincide with those of the super(12)CO emission, inconsistent with the prediction by the plane-parallel PDR model. In addition, the CI distribution in the Orion A cloud is found to be more similar to those of the super(13)CO (J = 1-0), C super(18)O (J = 1-0), and H super(13)CO super(+) (J = 1-0) lines than that of the super(12)CO (J = 1-0) line, suggesting that the CI emission is not limited to the cloud surface, but is tracing the dense, inner parts of the cloud.
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![EXTENSIVE [C I] MAPPING TOW...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/2041-8205_2041-8213/small "EXTENSIVE [C I] MAPPING TOWARD THE ORION-A GIANT MOLECULAR CLOUD")