_version_ 1866918219222089728
author Yonetsu, Teppei
Kawabe, Ryohei
Yoshimura, Yuki
Taniguchi, Kotomi
Shimajiri, Yoshito
Rojas-García, Omar Sergio
Gómez-Ruiz, Arturo I.
Sakai, Takeshi
Tanaka, Kunihiko
Hatsukade, Bunyo
Taniguchi, Akio
Tamura, Yoichi
Takekoshi, Tatsuya
Oshima, Tai
Kohno, Kotaro
Hagimoto, Masato
Hughes, David H.
Schloerb, Peter F.
Sánchez-Argüelles, David
Souccar, Kamal
Narayanan, Gopal
Yun, Min S.
Gómez-Rivera, Víctor
Rodríguez-Montoya, Iván
Colín-Beltrán, Edgar
Dagostino, Miguel Chávez
Zaragoza-Cardiel, Javier
Fujita, Shinji
Maezawa, Hiroyuki
author_facet Yonetsu, Teppei
Kawabe, Ryohei
Yoshimura, Yuki
Taniguchi, Kotomi
Shimajiri, Yoshito
Rojas-García, Omar Sergio
Gómez-Ruiz, Arturo I.
Sakai, Takeshi
Tanaka, Kunihiko
Hatsukade, Bunyo
Taniguchi, Akio
Tamura, Yoichi
Takekoshi, Tatsuya
Oshima, Tai
Kohno, Kotaro
Hagimoto, Masato
Hughes, David H.
Schloerb, Peter F.
Sánchez-Argüelles, David
Souccar, Kamal
Narayanan, Gopal
Yun, Min S.
Gómez-Rivera, Víctor
Rodríguez-Montoya, Iván
Colín-Beltrán, Edgar
Dagostino, Miguel Chávez
Zaragoza-Cardiel, Javier
Fujita, Shinji
Maezawa, Hiroyuki
contents We present the results of mapping and single-point spectral scans toward Orion-KL/OMC-1 performed as science demonstrations of a 2 mm SIS receiver, the Band 4 Receiver (B4R), installed on the 50 m Large Millimeter Telescope (LMT). To prove the capabilities of mapping and spectral scans with the B4R on the LMT, commissioning observations were conducted employing the on-the-fly mapping technique toward Orion-KL/OMC-1, which covers a map size of 5$'\times$5$'$. These mapping observations were performed with two frequency settings providing 10 GHz in total (131.4-133.9 GHz and 145.1-147.6 GHz; 136.2-138.7 GHz and 149.9-152.4 GHz) with a frequency resolution of 76.293 kHz. We conducted spectral line identification analysis for the hot core and compact ridge regions in the Orion-KL with a beam size of 11-12$''$. We detected nearly 400 emission lines and identified two recombination lines and 29 molecular species, including isotopologues, deuterated molecules, and vibrational excited states, despite the short integration time. These results are consistent with those of previous studies. The 29 molecular species include nitrogen (N)-bearing complex organic molecules (COMs) and oxygen (O)-bearing COMs. To demonstrate the capability of the B4R in astrochemistry, we conducted detailed analyses of column densities, rotational temperatures, and relative abundances with respect to H$_2$ on two representative COMs, N-bearing C$_2$H$_5$CN and O-bearing CH$_3$OCHO in the central 40$''\times$40$''$ area of the map. The wide bandwidth of 10 GHz enabled the use of 8 and 34 emission lines, respectively. The spatial differences in the physical and chemical properties between these molecules were derived at a spatial resolution of $\sim$12$''$. The B4R on the LMT was successfully demonstrated to be powerful for mapping and spectral scans and to have high potential for the study of interstellar chemistry.
format Preprint
id arxiv_https___arxiv_org_abs_2511_21845
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle The LMT 2 millimeter receiver system (B4R). II. Science demonstration observations toward Orion-KL/OMC-1
Yonetsu, Teppei
Kawabe, Ryohei
Yoshimura, Yuki
Taniguchi, Kotomi
Shimajiri, Yoshito
Rojas-García, Omar Sergio
Gómez-Ruiz, Arturo I.
Sakai, Takeshi
Tanaka, Kunihiko
Hatsukade, Bunyo
Taniguchi, Akio
Tamura, Yoichi
Takekoshi, Tatsuya
Oshima, Tai
Kohno, Kotaro
Hagimoto, Masato
Hughes, David H.
Schloerb, Peter F.
Sánchez-Argüelles, David
Souccar, Kamal
Narayanan, Gopal
Yun, Min S.
Gómez-Rivera, Víctor
Rodríguez-Montoya, Iván
Colín-Beltrán, Edgar
Dagostino, Miguel Chávez
Zaragoza-Cardiel, Javier
Fujita, Shinji
Maezawa, Hiroyuki
Astrophysics of Galaxies
We present the results of mapping and single-point spectral scans toward Orion-KL/OMC-1 performed as science demonstrations of a 2 mm SIS receiver, the Band 4 Receiver (B4R), installed on the 50 m Large Millimeter Telescope (LMT). To prove the capabilities of mapping and spectral scans with the B4R on the LMT, commissioning observations were conducted employing the on-the-fly mapping technique toward Orion-KL/OMC-1, which covers a map size of 5$'\times$5$'$. These mapping observations were performed with two frequency settings providing 10 GHz in total (131.4-133.9 GHz and 145.1-147.6 GHz; 136.2-138.7 GHz and 149.9-152.4 GHz) with a frequency resolution of 76.293 kHz. We conducted spectral line identification analysis for the hot core and compact ridge regions in the Orion-KL with a beam size of 11-12$''$. We detected nearly 400 emission lines and identified two recombination lines and 29 molecular species, including isotopologues, deuterated molecules, and vibrational excited states, despite the short integration time. These results are consistent with those of previous studies. The 29 molecular species include nitrogen (N)-bearing complex organic molecules (COMs) and oxygen (O)-bearing COMs. To demonstrate the capability of the B4R in astrochemistry, we conducted detailed analyses of column densities, rotational temperatures, and relative abundances with respect to H$_2$ on two representative COMs, N-bearing C$_2$H$_5$CN and O-bearing CH$_3$OCHO in the central 40$''\times$40$''$ area of the map. The wide bandwidth of 10 GHz enabled the use of 8 and 34 emission lines, respectively. The spatial differences in the physical and chemical properties between these molecules were derived at a spatial resolution of $\sim$12$''$. The B4R on the LMT was successfully demonstrated to be powerful for mapping and spectral scans and to have high potential for the study of interstellar chemistry.
title The LMT 2 millimeter receiver system (B4R). II. Science demonstration observations toward Orion-KL/OMC-1
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2511.21845