A Q-band Line Survey toward Orion KL Using the Tianma Radio Telescope

Liu, Xunchuan; Shen, Zhi-Qiang; Qin, Sheng-Li; Luo, Qijun; Cheng, Yu; Gu, Qilao; Zhu, Feng-Yao; Liu, Sheng-Yuan; Lu, Xing; Zhao, Rong-Bing; Zhong, Wang; Wu, Yajun; Zhang, Zhao; Wang, Jinqing; Liu, Qinghui; Xia, Bo; Li, Bin; Fu, Li; Yan, Zhen; Zhang, Chao; Wang, Lingling; Ye, Qian; Tatematsu, Ken’ichi; Liu, Hong-Li; Shang, Hsien; Xu, Fengrong; Lee, Chin-Fei; Dutta, Somnath

doi:10.3847/1538-4365/ac9127

Cited by 4 publications

(28 citation statements)

References 89 publications

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“…d Little can be known about the line survey of Ohishi et al (1986) from its relevant published work. From the spectra of all of its covered frequency bands , Ohishi et al (1986) detected 19 molecular species, much smaller than the values of 39 and 53 detected in Q band alone by Rizzo et al (2017) and Liu et al (2022).…”

Section: The Ka-band Surveymentioning

confidence: 71%

“…The ongoing TMRT line survey began with the Q-band (35-50 GHz) pioneer survey (Liu et al 2022), which is so far the most sensitive one compared with previous wide-band Qband surveys of Orion KL (Ohishi et al 1986;Rizzo et al 2017). It reached a sensitivity at a level of 1.5-5 mK (Table 1) and 597 Gaussian features were extracted, proving the capability for the TMRT of conducting deep-line surveys.…”

Section: Introductionmentioning

confidence: 93%

“…This Ka-band line survey of Orion KL covered 26.1-35 GHz. Although the working frequency range of the K-band receiver is 26-40 GHz, the 35-40 GHz was not covered by this survey, because it has been done by our previous Q-band line survey (Liu et al 2022). The 26-26.1 GHz was not Notes.…”

Section: The Ka-band Surveymentioning

confidence: 99%

“…The digital backend system (DIBAS) of TMRT is an FPGA-based spectrometer based on the design of the Versatile GBT Astronomical Spectrometer (Bussa & VEGAS Development Team 2012), and it provides 29 observing modes. The setup of the backend for the Ka-band survey is the same as that of the Q-band survey (Liu et al 2022). Two banks (the third one is not available at present) have a bandwidth of 1.5 GHz each, and they work independently with no limitation on the separation between their central frequencies.…”

Section: The Ka-band Surveymentioning

confidence: 99%

“…It makes the Ka band a missing piece for previous line surveys (Table 1). To fill in this blank gap, we conducted a Ka-band (26-35 GHz) survey of Orion KL as a part of the TMRT line survey, following the Q-band one (Liu et al 2022). Through long-time integrations, a line sensitivity of 1-3 mK was achieved with a frequency resolution of 91.553 kHz.…”

Section: Introductionmentioning

confidence: 99%

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The First Ka-band (26.1–35 GHz) Blind Line Survey toward Orion KL

Liu 刘,

Liu,

Shen

et al. 2024

ApJS

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We conducted a Ka-band (26.1–35 GHz) line survey toward Orion KL using the TianMa 65 m Radio Telescope (TMRT). It is the first blind line survey in the Ka band and achieves a sensitivity at the mK level (1–3 mK at a spectral resolution of ∼1 km s−1). In total, 592 Gaussian features are extracted. Among them, 257 radio recombination lines (RRLs) are identified. The maximum Δn of RRLs of H, He, and C are 20, 15, and 5, respectively. Through stacking, we have detected the β lines of ion RRLs (RRLs of C+ with the possible contribution of other ions like O+) for the first time, and a tentative signal of the γ lines of ion RRLs can also be seen on the stacked spectrum. Besides this, 318 other line features were assigned to 37 molecular species, and 10 of these species were not detected in the Q-band survey of TMRT. The vibrationally excited states of nine species were also detected. The emission of most species can be modeled under LTE. A number of transitions of E-CH3OH (J 2 − J 1) display maser effects, which are confirmed by our modeling, and besides the bumping peak at J ∼ 6, there is another peak at J ∼ 13. Methylcyanoacetylene (CH3C3N) is detected in Orion KL for the first time. This work emphasizes that the Ka band, which was long ignored for spectral line surveys, is very useful for surveying RRLs and molecular lines simultaneously.

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Section: The Ka-band Surveymentioning

confidence: 71%

Section: Introductionmentioning

confidence: 93%

Section: The Ka-band Surveymentioning

confidence: 99%

Section: The Ka-band Surveymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The First Ka-band (26.1–35 GHz) Blind Line Survey toward Orion KL

Liu 刘,

Liu,

Shen

et al. 2024

ApJS

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First detection of radio recombination lines of ions heavier than helium

Liu

Shen

et al. 2023

A&A

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We report the first detection of radio recombination lines (RRLs) of ions heavier than helium. In a highly sensitive multi-band (12–50 GHz) line survey toward Orion KL with the TianMa 65-m Radio Telescope (TMRT), we successfully detected more than fifteen unblended α lines of RRLs of singly ionized species (XII) recombined from XIII. The Ka-band (26–35 GHz) spectrum also shows tentative signals of β lines of ions. The detected lines can be successfully crossmatched with the rest frequencies of RRLs of C II and/or O II. This finding greatly expands the scope of our understanding of ion RRLs, since prior to this work, only two blended lines (105α and 121α) of He II had been reported. Our detected lines can be fitted simultaneously under assumption of local thermodynamic equilibrium (LTE). An abundance of C III and O III of 8.8×10−4 was obtained, avoiding the complexities of optical and infrared observations and the blending of RRLs of atoms. It is consistent with but approaches the upper bound of the value (10−4–10−3) estimated from optical and infrared observations. The effects of dielectronic recombination may contribute to enhancing the level populations even at large n. We expect future observations using radio interferometers could break the degeneracy between C and O, while also helping to reveal the ionization structure and dynamical evolution of various ionized regions.

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The ALMA-QUARKS Survey. I. Survey Description and Data Reduction

Liu 刘,

Liu,

Zhu

et al. 2024

Res. Astron. Astrophys.

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This paper presents an overview of the QUARKS survey, which stands for 'Querying Underlying mechanisms of massive star formation with ALMA-Resolved gas Kinematics and Structures'. The QUARKS survey is observing 139 massive gas clumps covered by 156 pointings at ALMA Band 6 (λ~1.3 mm). In conjunction with data obtained from the ALMA-ATOMS survey at Band 3 (λ~3 mm), QUARKS aims to carry out an unbiased statistical investigation of massive star formation process within protoclusters down to a scale of 1000 au. This overview paper describes the observations and data reduction of the QUARKS survey, and gives a first look at an exemplar source, the mini-starburst Sgr B2(M). The wide-bandwidth (7.5 GHz) and high-resolution (~0.3 arcsec) observations of the QUARKS survey allow to resolve much more compact cores than could be done by the ATOMS survey, and to detect fainter filamentary structures that were not revealed earlier. The spectral windows cover transitions of species including CO, SO, N2D+, SiO, H30α, H2CO, CH3CN and many other complex organic molecules, tracing gas components with different temperatures and spatial extents. QUARKS aims to deepen our understanding of several scientific topics of massive star formation, such as mass transport within protoclusters by (hub-)filamentary structures, the existence of massive starless cores, the physical and chemical properties of dense cores within protoclusters, and the feedback from already formed high-mass young protostars.

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A Q-band Line Survey toward Orion KL Using the Tianma Radio Telescope

Cited by 4 publications

References 89 publications

The First Ka-band (26.1–35 GHz) Blind Line Survey toward Orion KL

The First Ka-band (26.1–35 GHz) Blind Line Survey toward Orion KL

First detection of radio recombination lines of ions heavier than helium

The ALMA-QUARKS Survey. I. Survey Description and Data Reduction

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