Faculty Profiles - TAMURA Yoichi

DESHIMA 2.0: Development of an Integrated Superconducting Spectrometer for Science-Grade Astronomical Observations Reviewed

Akio Taniguchi, Tom J. L. C. Bakx, Jochem J. A. Baselmans, Robert Huiting, Kenichi Karatsu, Nuria Llombart, Matus Rybak, Tatsuya Takekoshi, Yoichi Tamura, Hiroki Akamatsu, Stefanie Brackenhoff, Juan Bueno, Bruno T. Buijtendorp, Shahab O. Dabironezare, Anne-Kee Doing, Yasunori Fujii, Kazuyuki Fujita, Matthijs Gouwerok, Sebastian Hähnle, Tsuyoshi Ishida, Shun Ishii, Ryohei Kawabe, Tetsu Kitayama, Kotaro Kohno, Akira Kouchi, Jun Maekawa, Keiichi Matsuda, Vignesh Murugesan, Shunichi Nakatsubo, Tai Oshima, Alejandro Pascual Laguna, David J. Thoen, Paul P. van der Werf, Stephen J. C. Yates, Akira Endo

Journal of Low Temperature Physics Vol. 209 ( 3-4 ) page： 278 - 286 2022.11

Language：English Publishing type：Research paper (scientific journal)

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.

DOI： 10.1007/s10909-022-02888-5

An AGN with an Ionized Gas Outflow in a Massive Quiescent Galaxy in a Protocluster at z = 3.09 Reviewed

Characterization of sensitivity and responses of a 2-element prototype wavefront sensor for millimeter-wave adaptive optics attached to the Nobeyama 45 m telescope

Satoya Nakano, Yoichi Tamura, Akio Taniguchi, Sachiko K. Okumura, Ryohei Kawabe, Nozomi Okada, Tomoko Nakamura, Yuhei Fukasaku

Proceedings of the SPIE Vol. 12185 page： 121856Z 2022.8

Development status of TAO/MIMIZUKU: performance test of the near-infrared channel Invited

Takafumi Kamizuka, Takashi Miyata, Shigeyuki Sako, Ryou Ohsawa, Kentaro Asano, Atsushi Nishimura, Kengo Tachibana, Tsubasa Michifuji, Hirokazu Iida, Akira C. Naruse, Mizuho Uchiyama, Itsuki Sakon, Takashi Onaka, Hirokazu Kataza, Sunao Hasegawa, Fumihiko Usui, Naruhisa Takato, Noboru Ebizuka, Takuya Hosobata, Tsutomu Aoki, Mamoru Doi, Fumi Egusa, Bunyo Hatsukade, Natsuko Kato, Kotaro Kohno, Masahiro Konishi, Shintaro Koshida, Shuhei Koyama, Takeo Minezaki, Tomoki Morokuma, Kentaro Motohara, Mizuki Numata, Hiroaki Sameshima, Hidenori Takahashi, Yoichi Tamura, Toshihiko Tanabe, Masuo Tanaka, Kosuke Kushibiki, Nuo Chen, Shogo Homan, Yuzuru Yoshii

Proceedings of the SPIE Vol. 12184 page： 121845J 2022.8

Mariko Kubo, Hideki Umehata, Yuichi Matsuda, Masaru Kajisawa, Charles C. Steidel, Toru Yamada, Ichi Tanaka, Bunyo Hatsukade, Yoichi Tamura, Kouichiro Nakanishi, Kotaro Kohno, Kianhong Lee, Keiichi Matsuda, Yiping Ao, Tohru Nagao, Min S. Yun

The Astrophysical Journal Vol. 935 ( 2 ) page： 89 - 89 2022.8

Language：English Publishing type：Research paper (scientific journal) Publisher：American Astronomical Society

Abstract

We report the detection of an ionized gas outflow from an X-ray active galactic nucleus hosted in a massive quiescent galaxy in a protocluster at z = 3.09 (J221737.29+001823.4). It is a type-2 QSO with broad (W80 > 1000 km s−1) and strong ($\mathrm{log}({L}_{[\mathrm{OIII}]}$/erg s−1) ≈ 43.4) [O iii]λλ 4959,5007 emission lines detected by slit spectroscopy in three-position angles using Multi-Object Infra-Red Camera and Spectrograph (MOIRCS) on the Subaru telescope and the Multi-Object Spectrometer For Infra-Red Exploration (MOSFIRE) on the Keck-I telescope. In the all slit directions, [O iii] emission is extended to ∼15 physical kpc and indicates a powerful outflow spreading over the host galaxy. The inferred ionized gas mass outflow rate is 22 ± 3 M⊙ yr−1. Although it is a radio source, according to the line diagnostics using Hβ, [O ii], and [O iii], photoionization by the central QSO is likely the dominant ionization mechanism rather than shocks caused by radio jets. On the other hand, the spectral energy distribution of the host galaxy is well characterized as a quiescent galaxy that has shut down star formation several hundred Myr ago. Our results suggest a scenario that QSOs are powered after the shutdown of the star formation and help complete the quenching of massive quiescent galaxies at high redshift.

DOI： 10.3847/1538-4357/ac7f2d

ALMA Reveals Extended Cool Gas and Hot Ionized Outflows in a Typical Star-forming Galaxy at Z = 7.13 Reviewed

Other Link： https://iopscience.iop.org/article/10.3847/1538-4357/ac7f2d/pdf

Hollis B. Akins, Seiji Fujimoto, Kristian Finlator, Darach Watson, Kirsten K. Knudsen, Johan Richard, Tom J.L. Tom, Takuya Hashimoto, Akio K. Inoue, Hiroshi Matsuo, Michał J. Michałowski, Yoichi Tamura

Astrophysical Journal Vol. 934 ( 1 ) page： 64 2022.7

Language：English Publishing type：Research paper (scientific journal)

We present spatially resolved morphological properties of [C II] 158 μm, [O III] 88 μm, dust, and rest-frame ultraviolet (UV) continuum emission for A1689-zD1, a strongly lensed, sub-L* galaxy at z = 7.13, by utilizing deep Atacama Large Millimeter/submillimeter Array (ALMA) and Hubble Space Telescope (HST) observations. While the [O III] line and UV continuum are compact, the [C II] line is extended up to a radius of r ∼ 12 kpc. Using multi-band rest-frame far-infrared continuum data ranging from 52 to 400 μm, we find an average dust temperature and emissivity index of T dust = 41 − 14 + 17 K and β = 1.7 − 0.7 + 1.1 , respectively, across the galaxy. We find slight differences in the dust continuum profiles at different wavelengths, which may indicate that the dust temperature decreases with distance. We map the star formation rate (SFR) via IR and UV luminosities and determine a total SFR of 37 ± 1M ⊙yr−1 with an obscured fraction of 87%. While the [O III] line is a good tracer of the SFR, the [C II] line shows deviation from the local L [C II]-SFR relations in the outskirts of the galaxy. Finally, we observe a clear difference in the line profile between [C II] and [O III], with significant residuals (∼5σ) in the [O III] line spectrum after subtracting a single Gaussian model. This suggests a possible origin of the extended [C II] structure from the cooling of hot ionized outflows. The extended [C II] and high-velocity [O III] emission may both contribute in part to the high L [O III]/L [C II] ratios recently reported in z > 6 galaxies.

DOI： 10.3847/1538-4357/ac795b

High-resolution ALMA Study of CO J = 2–1 Line and Dust Continuum Emissions in Cluster Galaxies at z = 1.46 Reviewed

Ryota Ikeda, Ken-ichi Tadaki, Daisuke Iono, Tadayuki Kodama, Jeffrey C. C. Chan, Bunyo Hatsukade, Masao Hayashi, Takuma Izumi, Kotaro Kohno, Yusei Koyama, Rhythm Shimakawa, Tomoko L. Suzuki, Yoichi Tamura, Ichi Tanaka

The Astrophysical Journal Vol. 933 ( 1 ) page： 11 - 11 2022.7

Language：English Publishing type：Research paper (scientific journal) Publisher：American Astronomical Society

Abstract

We present new Atacama Large Millimeter/submillimeter Array (ALMA) results obtained from spatially resolved CO J = 2–1 line (0.″4 resolution) and 870 μm continuum (0.″2 resolution) observations of cluster galaxies in XMMXCS J2215.9-1738 at z = 1.46. Our sample comprises 17 galaxies within ∼0.5 Mpc (0.6R200) of the cluster center, all of which have previously been detected in the CO J = 2–1 line at a lower resolution. The effective radii of both the CO J = 2–1 line and 870 μm dust continuum emissions are robustly measured for nine galaxies by modeling the visibilities. We find that the CO J = 2–1 line emission in all of the nine galaxies is more extended than the dust continuum emission by a factor of 2.8 ± 1.4. We investigate the spatially resolved Kennicutt–Schmidt (KS) relation in two regions within the interstellar medium of the galaxies. The relation for our sample reveals that the central region (0 < r < Re,870μm) of galaxies tends to have a shorter gas depletion timescale, i.e., a higher star formation efficiency, compared to the extended region (Re,870μm < r < Re,CO). Overall, our result suggests that star formation activities are concentrated inside the extended gas reservoir, possibly resulting in the formation of a bulge structure. We find consistency between the ALMA 870 μm radii of star-forming members and the Hubble Space Telescope/1.6 μm radii of passive members in a mass–size distribution, which suggests a transition from star-forming to passive members within ∼0.5 Gyr. In addition, no clear differences in the KS relation nor in the sizes are found between galaxies with and without a close companion.

DOI： 10.3847/1538-4357/ac6cdc

Other Link： https://iopscience.iop.org/article/10.3847/1538-4357/ac6cdc/pdf

Possible Systematic Rotation in the Mature Stellar Population of a z=9.1 Galaxy

Tokuoka Tsuyoshi, Inoue Akio K., Hashimoto Takuya, Ellis Richard S., Laporte Nicolas, Sugahara Yuma, Matsuo Hiroshi, Tamura Yoichi, Fudamoto Yoshinobu, Moriwaki Kana, Roberts-Borsani Guido, Shimizu Ikkoh, Yamanaka Satoshi, Yoshida Naoki, Zackrisson Erik, Zheng Wei

ASTROPHYSICAL JOURNAL LETTERS Vol. 933 ( 1 ) 2022.7

Detection of nitrogen and oxygen in a galaxy at the end of reionization Reviewed

Ken-ichi Tadaki, Akiyoshi Tsujita, Yoichi Tamura, Kotaro Kohno, Bunyo Hatsukade, Daisuke Iono, Minju M Lee, Yuichi Matsuda, Tomonari Michiyama, Tohru Nagao, Kouichiro Nakanishi, Yuri Nishimura, Toshiki Saito, Hideki Umehata, Jorge Zavala

Publications of the Astronomical Society of Japan Vol. 74 ( 3 ) page： L9 - L16 2022.6

Language：English Publishing type：Research paper (scientific journal) Publisher：Oxford University Press (OUP)

Abstract

We present observations of [N ii] 205 μm, [O iii] 88 μm, and dust emission in a strongly-lensed, submillimeter galaxy (SMG) at z = 6.0, G09.83808, with the Atacama Large Millimeter/submillimeter Array (ALMA). Both [N ii] and [O iii] line emissions are detected at &gt;12σ in the ${0{^{\prime \prime}_{. } }8}$-resolution maps. Lens modeling indicates that the spatial distribution of the dust continuum emission is well characterized by a compact disk with an effective radius of 0.64 ± 0.02 kpc and a high infrared surface brightness of ΣIR = (1.8 ± 0.3) × 1012 L⊙ kpc−2. This result supports that G09.83808 is the progenitor of compact quiescent galaxies at z ∼ 4, where the majority of its stars are expected to be formed through a strong and short burst of star formation. G09.83808 and other lensed SMGs show a decreasing trend in the [N ii] line to infrared luminosity ratio with increasing continuum flux density ratio between 63 and 158 μm, as seen in local luminous infrared galaxies (LIRGs). The decreasing trend can be reproduced by photoionization models with increasing ionization parameters. Furthermore, by combining the [N ii]/[O iii] luminosity ratio with far-infrared continuum flux density ratio in G09.83808, we infer that the gas phase metallicity is already Z ≈ 0.5–0.7 Z⊙. G09.83808 is likely one of the earliest galaxies that has been chemically enriched at the end of reionization.

DOI： 10.1093/pasj/psac018

The bright extragalactic ALMA redshift survey (BEARS) I: Redshifts of bright gravitationally lensed galaxies from the Herschel ATLAS

Properties of molecular gas in galaxies in early and mid stages of Interaction. III. Resolved Kennicutt–Schmidt law Invited Reviewed

Hiroyuki Kaneko, Nario Kuno, Daisuke Iono, Yoichi Tamura, Tomoka Tosaki, Kouichiro Nakanishi, Tsuyoshi Sawada

Publications of the Astronomical Society of Japan Vol. 74 ( 2 ) page： 343 - 363 2022.4

Urquhart S.A., Bendo G.J., Serjeant S., Bakx T., Hagimoto M., Cox P., Neri R., Lehnert M., Sedgwick C., Weiner C., Dannerbauer H., Amvrosiadis A., Andreani P., Baker A.J., Beelen A., Berta S., Borsato E., Buat V., Butler K.M., Cooray A., De Zotti G., Dunne L., Dye S., Eales S., Enia A., Fan L., Gavazzi R., González-Nuevo J., Harris A.I., Herrera C.N., Hughes D., Ismail D., Ivison R., Jin S., Jones B., Kohno K., Krips M., Lagache G., Marchetti L., Massardi M., Messias H., Negrello M., Omont A., Perez-Fournon I., Riechers D.A., Scott D., Smith M.W.L., Stanley F., Tamura Y., Temi P., Vlahakis C., Weiß A., Van Der Werf P., Verma A., Yang C., Young A.J.

Monthly Notices of the Royal Astronomical Society Vol. 511 ( 2 ) page： 3017 - 3033 2022.4

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Monthly Notices of the Royal Astronomical Society

We present spectroscopic measurements for 71 galaxies associated with 62 of the brightest high-redshift submillimetre sources from the Southern fields of the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS), while targeting 85 sources which resolved into 142. We have obtained robust redshift measurements for all sources using the 12-m Array and an efficient tuning of ALMA to optimize its use as a redshift hunter, with 73 per cent of the sources having a robust redshift identification. Nine of these redshift identifications also rely on observations from the Atacama Compact Array. The spectroscopic redshifts span a range 1.41 < z < 4.53 with a mean value of 2.75, and the CO emission line full-width at half-maxima range between 110, km, s-1 < FWHM < 1290, km, s-1 with a mean value of ∼500 km s-1, in line with other high-z samples. The derived CO(1-0) luminosity is significantly elevated relative to line-width to CO(1-0) luminosity scaling relation, which is suggestive of lensing magnification across our sources. In fact, the distribution of magnification factors inferred from the CO equivalent widths is consistent with expectations from galaxy-galaxy lensing models, though there is a hint of an excess at large magnifications that may be attributable to the additional lensing optical depth from galaxy groups or clusters.

DOI： 10.1093/mnras/stac150

A Search for H-Dropout Lyman Break Galaxies at z ∼ 12–16 Reviewed

Yuichi Harikane, Akio K. Inoue, Ken Mawatari, Takuya Hashimoto, Satoshi Yamanaka, Yoshinobu Fudamoto, Hiroshi Matsuo, Yoichi Tamura, Pratika Dayal, L. Y. Aaron Yung, Anne Hutter, Fabio Pacucci, Yuma Sugahara, Anton M. Koekemoer

The Astrophysical Journal Vol. 929 ( 1 ) page： 1 - 1 2022.4

Language：English Publishing type：Research paper (scientific journal) Publisher：American Astronomical Society

Abstract

We present two bright galaxy candidates at z ∼ 12–13 identified in our H-dropout Lyman break selection with 2.3 deg2 near-infrared deep imaging data. These galaxy candidates, selected after careful screening of foreground interlopers, have spectral energy distributions showing a sharp discontinuity around 1.7 μm, a flat continuum at 2–5 μm, and nondetections at <1.2 μm in the available photometric data sets, all of which are consistent with a z > 12 galaxy. An ALMA program targeting one of the candidates shows a tentative 4σ [O iii] 88 μm line at z = 13.27, in agreement with its photometric redshift estimate. The number density of the z ∼ 12–13 candidates is comparable to that of bright z ∼ 10 galaxies and is consistent with a recently proposed double-power-law luminosity function rather than the Schechter function, indicating little evolution in the abundance of bright galaxies from z ∼ 4 to 13. Comparisons with theoretical models show that the models cannot reproduce the bright end of rest-frame ultraviolet luminosity functions at z ∼ 10–13. Combined with recent studies reporting similarly bright galaxies at z ∼ 9–11 and mature stellar populations at z ∼ 6–9, our results indicate the existence of a number of star-forming galaxies at z > 10, which will be detected with upcoming space missions such as the James Webb Space Telescope, Nancy Grace Roman Space Telescope, and GREX-PLUS.

DOI： 10.3847/1538-4357/ac53a9

TiEMPO: open-source time-dependent end-to-end model for simulating ground-based submillimeter astronomical observations

Other Link： https://iopscience.iop.org/article/10.3847/1538-4357/ac53a9/pdf

Huijten Esmee, Roelvink Yannick, Brackenhoff Stefanie A., Taniguchi Akio, Bakx Tom J. L. C., Marthi Kaushal B., Zaalberg Stan, Doing Anne-Kee, Baselmans Jochem J. A., Chin Kah Wuy, Huiting Robert, Karatsu Kenichi, Laguna Alejandro Pascual, Tamura Yoichi, Takekoshi Tatsuya, Yates Stephen J. C., van Hoven Maarten, Endo Akira

JOURNAL OF ASTRONOMICAL TELESCOPES INSTRUMENTS AND SYSTEMS Vol. 8 ( 2 ) 2022.4

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Astronomical Telescopes, Instruments, and Systems

The next technological breakthrough in millimeter–submillimeter astronomy is three-dimensional imaging spectrometry with wide instantaneous spectral bandwidths and wide fields of view. The total optimization of the focal-plane instrument, the telescope, the observing strategy, and the signal-processing software must enable efficient removal of foreground emission from the Earth’s atmosphere, which is time-dependent and highly nonlinear in frequency. Here, we present Time-dependent End-to-end Model for Post-process Optimization (TiEMPO) of the DEep Spectroscopic HIgh-redshift MApper (DESHIMA) spectrometer. TiEMPO utilizes a dynamical model of the atmosphere and parameterized models of the astronomical source, the telescope, the instrument, and the detector. The output of TiEMPO is a time stream of sky brightness temperature and detected power, which can be analyzed by standard signal-processing software. We first compare TiEMPO simulations with an on-sky measurement by the wideband DESHIMA spectrometer, and find good agreement in the noise and sensitivity. We then use TiEMPO to simulate the detection of the line emission spectrum of a high-redshift galaxy using the DESHIMA 2.0 spectrometer in development. The TiEMPO model is open source. Its modular and parametrized design enables users to adapt it to optimize the end-to-end performance of spectroscopic and photometric instruments on existing and future telescopes

DOI： 10.1117/1.JATIS.8.2.028005

The Kiloparsec-scale Neutral Atomic Carbon Outflow in the Nearby Type 2 Seyfert Galaxy NGC 1068: Evidence for Negative AGN Feedback Reviewed

Toshiki Saito, Shuro Takano, Nanase Harada, Taku Nakajima, Eva Schinnerer, Daizhong Liu, Akio Taniguchi, Takuma Izumi, Yumi Watanabe, Kazuharu Bamba, Eric Herbst, Kotaro Kohno, Yuri Nishimura, Sophia Stuber, Yoichi Tamura, Tomoka Tosaki

The Astrophysical Journal Letters Vol. 927 ( 2 ) page： L32 - L32 2022.3

Language：English Publishing type：Research paper (scientific journal) Publisher：American Astronomical Society

Abstract

Active galactic nucleus (AGN) feedback is postulated as a key mechanism for regulating star formation within galaxies. Studying the physical properties of the outflowing gas from AGNs is thus crucial for understanding the coevolution of galaxies and supermassive black holes. Here we report 55 pc resolution ALMA neutral atomic carbon [C i] 3P1−3P0 observations toward the central 1 kpc of the nearby Type 2 Seyfert galaxy NGC 1068, supplemented by 55 pc resolution CO(J = 1−0) observations. We find that [C i] emission within the central kiloparsec is strongly enhanced by a factor of >5 compared to the typical [C i]/CO intensity ratio of ∼0.2 for nearby starburst galaxies (in units of brightness temperature). The most [C i]-enhanced gas (ratio > 1) exhibits a kiloparsec-scale elongated structure centered at the AGN that matches the known biconical ionized gas outflow entraining molecular gas in the disk. A truncated, decelerating bicone model explains well the kinematics of the elongated structure, indicating that the [C i] enhancement is predominantly driven by the interaction between the ISM in the disk and the highly inclined ionized gas outflow (which is likely driven by the radio jet). Our results strongly favor the “CO dissociation scenario” rather than the “in situ C formation” one, which prefers a perfect bicone geometry. We suggest that the high-[C i]/CO intensity ratio gas in NGC 1068 directly traces ISM in the disk that is currently dissociated and entrained by the jet and the outflow, i.e., the “negative” effect of the AGN feedback.

DOI： 10.3847/2041-8213/ac59ae

The Kiloparsec-scale Neutral Atomic Carbon Outflow in the Nearby Type 2 Seyfert Galaxy NGC 1068 : Evidence for Negative AGN Feedback Reviewed

Other Link： https://iopscience.iop.org/article/10.3847/2041-8213/ac59ae/pdf

Properties of molecular gas in galaxies in early and mid stages of Interaction. III. Resolved Kennicutt-Schmidt law

Kaneko Hiroyuki, Kuno Nario, Iono Daisuke, Tamura Yoichi, Tosaki Tomoka, Nakanishi Kouichiro, Sawada Tsuyoshi

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN 2022.2

Characterization of sensitivity and responses of a 2-element prototype wavefront sensor for millimeter-wave adaptive optics attached to the Nobeyama 45 m telescope

Satoya Nakano, Yoichi Tamura, Akio Taniguchi, Sachiko K. Okumura, Ryohei Kawabe, Nozomi Okada, Tomoko Nakamura, Yuhei Fukasaku

Adaptive Optics Systems VIII Vol. 12185 page： 121856Z 2022

Development status of TAO/MIMIZUKU: performance test of the near-infrared channel

Ground-based and Airborne Instrumentation for Astronomy IX Vol. 12184 2022

Vol. 927 ( L32 ) 2022

Big Three Dragons: A [N ii] 122 μm Constraint and New Dust-continuum Detection of a z = 7.15 Bright Lyman-break Galaxy with ALMA

Yuma Sugahara, Akio K. Inoue, Takuya Hashimoto, Satoshi Yamanaka, Seiji Fujimoto, Yoichi Tamura, Hiroshi Matsuo, Christian Binggeli, Erik Zackrisson

The Astrophysical Journal Vol. 923 ( 1 ) 2021.12

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：IOP Publishing Ltd

We present new Atacama Large Millimeter/submillimeter Array Band 7 observational results of a Lyman-break galaxy at z = 7.15, B14-65666 ("Big Three Dragons"), which is an object detected in [O III] 88 mu m, [CII] 158 mu m, and dust continuum emission during the epoch of reionization. Our targets are the [N II] 122 mu m fine-structure emission line and the underlying 120 mu m dust continuum. The dust continuum is detected with a similar to 19 sigma significance. From far-infrared spectral energy distribution sampled at 90, 120, and 160 mu m, we obtain a best-fit dust temperature of 40 K (79 K) and an infrared luminosity of log(10)(L-IR/L-circle dot)=11.6 <i (12.1) at the emissivity index beta = 2.0 (1.0). The [N II] 122 mu m line is not detected. The 3 sigma upper limit of the [N II] luminosity is 8.1 x 10(7) L-circle dot. From the [N II], [O III], and [C II] line luminosities, we use the Cloudy photoionization code to estimate nebular parameters as functions of metallicity. If the metallicity of the galaxy is high (Z > 0.4 Z(circle dot)), the ionization parameter and hydrogen density are log(10)U similar or equal to-2.7 +/- 0.1 n(H) similar or equal to 50-250 cm(-3), respectively, which are comparable to those measured in low-redshift galaxies. The nitrogen-to-oxygen abundance ratio, N/O, is constrained to be subsolar. At Z < 0.4 Z(circle dot), the allowed U drastically increases as the assumed metallicity decreases. For high ionization parameters, the N/O constraint becomes weak. Finally, our Cloudy models predict the location of B14-65666 on the BPT diagram, thereby allowing a comparison with low-redshift galaxies.

DOI： 10.3847/1538-4357/ac2a36