Marcelino Agúndez

Marcelino Agúndez
Instituto de Ciencia de Materiales de Madrid | ICMM

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273
Publications
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6,751
Citations
Citations since 2016
176 Research Items
4801 Citations
201620172018201920202021202202004006008001,000
201620172018201920202021202202004006008001,000
201620172018201920202021202202004006008001,000
201620172018201920202021202202004006008001,000

Publications

Publications (273)
Article
Full-text available
We present interferometric continuum and molecular line emission maps obtained with the Atacama Large Millimeter/submillimeter Array (ALMA) of OH231.8+4.2, a well studied bipolar nebula around an asymptotic giant branch (AGB) star that is key to understand the remarkable changes in nebular morphology and kinematics during the short transition from...
Preprint
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We report the detection of magnesium dicarbide, MgC$_2$, in the laboratory at centimeter wavelengths and assign $^{24}$MgC$_2$, $^{25}$MgC$_2$, and $^{26}$MgC$_2$ to 14 unidentified lines in the radio spectrum of the circumstellar envelope of the evolved carbon star IRC+10216. The structure of MgC$_2$ is found to be T-shaped with a highly ionic bon...
Preprint
Full-text available
Red supergiant stars (RSGs, Minit = 10-40Msun) are known to eject large amounts of material, as much as half of their initial mass during this evolutionary phase. However, the processes powering the mass ejection in low- and intermediate-mass stars do not work for RSGs and the mechanism that drives the ejection remains unknown. Different mechanisms...
Article
Full-text available
We report on the discovery of two new molecules, HCCCHCCC and HCCCCS, towards the starless core TMC-1 in the Taurus region from the QUIJOTE line survey in the 31.1–50.2 GHz frequency range. We identify a total of twenty-nine lines of HCCCHCCC and six rotational transitions of HCCCCS. The rotational quantum numbers range from J u = 10 up to 15 and K...
Preprint
We report on the discovery of two new molecules, HCCCHCCC and HCCCCS, towards the starless core TMC-1 in the Taurus region from the QUIJOTE line survey in the 31.1-50.2 GHz frequency range. We identify a total of twenty-nine lines of HCCCHCCC and six rotational transitions of HCCCCS. The rotational quantum numbers range from Ju=10 up to 15 and Ka <...
Article
Full-text available
We present the 3mm spectral line survey performed at the IRAM 30m telescope towards the dense cores B1-b and TMC-1. Within the 46 GHz observed, we have identified more than 500 lines arising from more than 60 molecules. We have also detected tens of unidentified lines, allowing the discovery of new molecular species in space. In this contribution w...
Article
Full-text available
We present the recent results obtained with the QUIJOTE line survey of the cold dark core TMC-1. The observations have been carried out with the YEBES 40m radio telescope (see Figure 1) in the Q-band (31-50 GHz). A new set of receivers have been installed in the telescope within the frame of the ERC synergy Nanocosmos project that allows to cover t...
Article
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The ejecta of evolved stars are among the most efficient chemical laboratories in the Universe. Many of the chemical compounds synthesized in these environments probably travel along the interstellar medium and may be ultimately delivered to planets. However, we still do not understand many of the chemical processes at work during the evolution fro...
Article
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We report the detection of fulvenallene ( c -C 5 H 4 CCH 2 ) in the direction of TMC-1 with the QUIJOTE ¹ line survey. Thirty rotational transitions with K a = 0,1,2,3 and J = 9−15 were detected. The best rotational temperature fitting of the data is 9 K and a derived column density is (2.7 ± 0.3) × 10 ¹² cm ⁻² , which is only a factor of 4.4 below...
Preprint
We report the detection of fulvenallene ($c$-C$_5$H$_4$CCH$_2$) in the direction of TMC-1 with the QUIJOTE line survey. Thirty rotational transitions with $K_a$=0,1,2,3 and $J$=9-15 were detected. The best rotational temperature fitting of the data is 9\,K and a derived column density is (2.7$\pm$0.3)$\times$10$^{12}$ cm$^{-2}$, which is only a fac...
Article
Full-text available
We report the discovery of five cyano derivatives of propene towards TMC-1 with the QUIJOTE line survey: trans and cis -crotononitrile ( t -CH 3 CHCHCN, c -CH 3 CHCHCN), methacrylonitrile (CH 2 C(CH 3 )CN), and gauche and cis -allyl cyanide ( g -CH 2 CHCH 2 CN and c -CH 2 CHCH 2 CN). The observed transitions allowed us to derive a common rotational...
Preprint
We report the discovery of five cyano derivatives of propene towards TMC-1 with the QUIJOTE line survey: $trans$ and $cis$-crotononitrile ($t$-CH$_3$CHCHCN, $c$-CH$_3$CHCHCN), methacrylonitrile (CH$_2$C(CH$_3$)CN), and $gauche$ and $cis$-allyl cyanide ($g$-CH$_2$CHCH$_2$CN and $c$-CH$_2$CHCH$_2$CN). The observed transitions allowed us to derive a c...
Article
Full-text available
Using the QUIJOTE line survey in the 32.0–50.4 GHz range, we report the discovery of the molecule CH 2 CCHC 4 H towards the prestellar cold core TMC-1 in the Taurus region. We also present a rigorous detection of CH 2 CCHC 3 N, along with its detailed analysis. We identified a total of twenty rotational transitions for each one of these molecules....
Preprint
Using the QUIJOTE line survey in the 32.0-50.4 GHz range, we report the discovery of the molecule CH2CCHC4H towards the prestellar cold core TMC-1 in the Taurus region. We also present a rigorous detection of CH2CCHC3N, along with its detailed analysis. We identified a total of twenty rotational transitions for each one of these molecules. The rota...
Preprint
Full-text available
Cyclic C5H (c-C5H), the radical formed by substituting an ethynyl group CCH for the hydrogen atom in the c-C3H radical, has been detected for the first time in the space. The c-C5H species is an isomer of the well-known linear radical l-C5H and is 6 kcal/mol less stable. A total of 17 rotational transitions were detected for the c-C5H species in TM...
Article
In recent years we have seen an important increase in the number of protonated molecules detected in cold dense clouds. Here we report the detection in TMC-1 of HCCNCH ⁺ , the protonated form of HCCNC, which is a metastable isomer of HC 3 N. This is the first protonated form of a metastable isomer detected in a cold dense cloud. The detection was b...
Preprint
Full-text available
In recent years we have seen an important increase in the number of protonated molecules detected in cold dense clouds. Here we report the detection in TMC-1 of HCCNCH+, the protonated form of HCCNC, which is a metastable isomer of HC3N. This is the first protonated form of a metastable isomer detected in a cold dense cloud. The detection was based...
Article
We report the detection of the protonated form of HC 7 N in TMC-1. The discovery of the cation HC 7 NH ⁺ was carried out via the observation of nine harmonically related lines in the Q -band using the Yebes 40 m radiotelescope. The observed frequencies allowed us to obtain the rotational constants B 0 = 553.938802 (160) MHz and D 0 = 3.6292 (705) H...
Article
Full-text available
PN M 1–92, also known as Minkowski’s Footprint, is a textbook example of a massive pre-planetary nebula. It presents all the characteristics of this type of source: non-spherical symmetry (bipolar cylindrical symmetry in this case), high-velocity gas emission, large amounts of linear momentum and kinetic energy (momentum excess), and a self-similar...
Preprint
Full-text available
We report the detection of the protonated form of HC7N in TMC-1. The discovery of the cation HC7NH+ was carried out via the observation of nine harmonically related lines in the Q-band using the Yebes 40m radiotelescope. The observed frequencies allowed us to obtain the rotational constants B_0=553.938802(160)MHz and D_0=3.6292(705) Hz. The identif...
Article
We report the discovery of the C 5 H ⁺ cation toward TMC-1 with the QUIJOTE line survey. Four lines from J = 7 − 6 up to J = 10 − 9 have been identified in perfect harmonic frequency relation that can be fit with B = 2411.94397 ± 0.00055 MHz and D = 138 ± 3 Hz. The standard deviation of the fit is 4.4 kHz. After discarding potential candidates, C 5...
Preprint
Full-text available
We report the discovery of the C5H+ cation toward TMC-1 with the QUIJOTE line survey. Four lines from J=7-6 up to J=10-9 have been identified in perfect harmonic frequency relation that can be fit with B=2411.94397 +/-0.00055 MHz and D=138+/-3 Hz. The standard deviation of the fit is 4.4 kHz. After discarding potential candidates, C5H- among them,...
Article
We report the first detection in space of the single deuterated isotopologue of methyldiacetylene, CH 2 DC 4 H. A total of 12 rotational transitions, with J = 8–12 and K a = 0 and 1, were identified for this species in TMC-1 in the 31.0–50.4 GHz range using the Yebes 40m radio telescope. The observed frequencies allowed us to obtain, for the first...
Article
We report the detection in TMC-1 of the cation HCCS ⁺ ( X̃ ³ Σ ⁻ ), which is the protonated form of the widespread radical CCS. This is the first time that a protonated radical has been detected in a cold dark cloud. Twenty-six hyperfine components from twelve rotational transitions have been observed with the Yebes 40 m and IRAM 30m radio telescop...
Preprint
Full-text available
We report the detection in TMC-1 of the cation HCCS+ (3Sigma-), which is the protonated form of the widespread radical CCS. This is the first time that a protonated radical has been detected in a cold dark cloud. Twenty-six hyperfine components from twelve rotational transitions have been observed with the Yebes 40m and IRAM 30m radio telescopes. W...
Preprint
Full-text available
We report the first detection in space of the single deuterated isotopologue of methyldiacetylene, CH2DC4H. A total of 12 rotational transitions, with J = 8-12 and Ka = 0 and 1, were identified for this species in TMC-1 in the 31.0-50.4 GHz range using the Yebes 40m radio telescope. The observed frequencies allowed us to obtain, for the first time,...
Article
Context. The reaction between carbon atoms and vinyl cyanide, CH 2 CHCN, is a formation route to interstellar 3-cyano propargyl radical, CH 2 C 3 N, a species that has recently been discovered in space. The 1-cyano propargyl radical (HC 3 HCN), an isomer of CH 2 C 3 N, is predicted to be produced in the same reaction at least twice more efficiently...
Article
We report the detection of the propargyl radical (CH 2 CCH) in the cold dark cloud TMC-1 in the λ 3 mm wavelength band. We recently discovered this species in space toward the same source at a wavelength of λ 8 mm. In those observations, various hyperfine components of the 2 0,2 –1 0,1 rotational transition, at 37.5 GHz, were detected using the Yeb...
Preprint
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We report the detection of the propargyl radical (CH2CCH) in the cold dark cloud TMC-1 in the lambda 3 mm wavelength band. We recently discovered this species in space toward the same source at a wavelength of lambda 8 mm. In those observations, various hyperfine components of the 2,0,2-1,0,1 rotational transition, at 37.5 GHz, were detected using...
Article
We report on the detection, for the first time in space, of the radical HCCCO and of pentacarbon monoxide, C 5 O. The derived column densities are (1.6 ± 0.2) × 10 ¹¹ cm ⁻² and (1.5 ± 0.2) × 10 ¹⁰ cm ⁻² , respectively. We have also analysed the data for all the molecular species of the families HC n O and C n O within our QUIJOTE’s line survey. Upp...
Preprint
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We report on the detection, for the first time in space, of the radical HCCCO and of pentacarbon monoxide, C5O. The derived column densities are (1.6+/-0.2)e11 cm-2 and (1.5+/-0.2)e10 cm-2, respectively. We have also analysed the data for all the molecular species of the families HCnO and CnO within our QUIJOTE line survey. Upper limits are obtaine...
Article
Context. The carbon-rich envelope of the asymptotic giant branch star CW Leo, IRC+10216, is one of the richest molecular sources in the sky. Available spectral surveys below 51 GHz are more than 25 years old, and new work is needed. Aims. Characterizing the rich molecular content of this source, specially for heavy species, requires carrying out ve...
Preprint
Full-text available
The reaction between carbon atoms and vinyl cyanide, CH2CHCN, is a formation route to interstellar 3-cyano propargyl radical, CH2C3N, a species that has recently been discovered in space. The 1-cyano propargyl radical (HC3HCN), an isomer of CH2C3N, is predicted to be produced in the same reaction at least twice more effciently than CH2C3N. Hence, H...
Article
We report the detection of two isomers of ethynyl cyclopentadiene ( c -C 5 H 5 CCH), namely 1- and 2-ethynyl-1,3-cyclopentadiene, in the direction of TMC-1. We derive column densities of (1.4 ± 0.2) × 10 ¹² cm ⁻² and (2.0 ± 0.4) × 10 ¹² cm ⁻² , respectively, for these two cyclopentadiene derivatives, which imply that they are about ten times less a...
Preprint
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We report the detection of two isomers of ethynyl cyclopentadiene (c-C5H5CCH), namely 1- and 2-ethynyl-1,3-cyclopentadiene, in the direction of TMC-1. We derive column densities of (1.4 +/- 0.2)e12 cm-2, and (2.0 +/- 0.4)e12 cm-2, respectively, for these two cyclopentadiene derivatives, which imply that they are about ten times less abundant than c...
Article
We report the first identification in space of H 2 NC, a high-energy isomer of H 2 CN that has been largely ignored in chemical and astrochemical studies. The observation of various unidentified lines around 72.2 GHz in the cold dark cloud L483 motivated the search and successful detection of additional groups of lines in harmonic relation. Followi...
Article
We report the detection, for the first time in space, of a new non-functionalised hydrocarbon cycle in the direction of TMC-1: o -C 6 H 4 (ortho-benzyne). We derive a column density for this hydrocarbon cycle of (5.0 ± 1.0) × 10 ¹¹ cm ⁻² . The abundance of this species is around 30 times lower than that of cyclopentadiene and indene. We compare the...
Article
After the previous discovery of MgC 3 N and MgC 4 H in IRC +10216, a deeper Q -band (31.0–50.3 GHz) integration on this source had revealed two additional series of harmonically related doublets that we assigned on the basis of quantum mechanical calculations to the larger radicals MgC 5 N and MgC 6 H. The results presented here extend and confirm...
Preprint
Full-text available
We report the detection, for the first time in space, of a new non-functionalised hydrocarbon cycle in the direction of TMC-1: o-C6H4 (ortho-benzyne). We derive a column density for this hydrocarbon cycle of (5 +/- 1)e11 cm-2. The abundance of this species is around 30 times lower than that of cyclopentadiene and indene. We compare the abundance of...
Preprint
Full-text available
After the previous discovery of MgC$_3$N and MgC$_4$H in IRC+10216, a deeper Q-band (31.0-50.3 GHz) integration on this source had revealed two additional series of harmonically related doublets that we assigned on the basis of quantum mechanical calculations to the larger radicals MgC$_5$N and MgC$_6$H. The results presented here extend and confir...
Preprint
Full-text available
We report the first identification in space of H2NC, a high-energy isomer of H2CN that has been largely ignored in chemical and astrochemical studies. The observation of various unidentified lines around 72.2 GHz in the cold dark cloud L483 motivated the search for, and successful detection of, additional groups of lines in harmonic relation. After...
Article
We report the first detection in space of the single deuterated isotopologue of methylcyanoacetylene, CH 2 DC 3 N. A total of 15 rotational transitions, with J = 8–12 and K a = 0 and 1, were identified for this species in TMC-1 in the 31.0–50.4 GHz range using the Yebes 40 m radio telescope. The observed frequencies were used to derive for the firs...
Article
We report the first detection in space of the cumulene carbon chain l -H 2 C 5 . A total of eleven rotational transitions, with J up = 7−10 and K a = 0 and 1, were detected in TMC-1 in the 31.0–50.4 GHz range using the Yebes 40 m radio telescope. We derived a column density of (1.8 ± 0.5)×10 ¹⁰ cm ⁻² . In addition, we report observations of other c...
Preprint
Full-text available
We report the first detection in space of the single deuterated isotopologue of methylcyanoacetylene, CH$_2$DC$_3$N. A total of fifteen rotational transitions, with $J$ = 8-12 and $K_a$ = 0 and 1, were identified for this species in TMC-1 in the 31.0-50.4 GHz range using the Yebes 40m radio telescope. The observed frequencies were used to derive fo...
Preprint
Full-text available
We report the first detection in space of the cumulene carbon chain $l$-H$_2$C$_5$. A total of eleven rotational transitions, with $J_{up}$ = 7-10 and $K_a$ = 0 and 1, were detected in TMC-1 in the 31.0-50.4 GHz range using the Yebes 40m radio telescope. We derive a column density of (1.8$\pm$0.5)$\times$10$^{10}$ cm$^{-2}$. In addition, we report...
Article
We report the detection, for the first time in space, of cyano thioformaldehyde (HCSCN) and propynethial (HCSCCH) towards the starless core TMC-1. Cyano thioformaldehyde presents a series of prominent a - and b -type lines, which are the strongest previously unassigned features in our Q -band line survey of TMC-1. Remarkably, HCSCN is four times mo...
Preprint
Full-text available
We report the detection, for the first time in space, of cyano thioformaldehyde (HCSCN) and propynethial (HCSCCH) towards the starless core TMC-1. Cyano thioformaldehyde presents a series of prominent a- and b-type lines, which are the strongest previously unassigned features in our Q-band line survey of TMC-1. Remarkably, HCSCN is four times more...
Article
Aims. We investigate the structure, dynamics, and chemistry of the molecule-rich nebula around the stellar symbiotic system R Aqr, which is significantly affected by the presence of a white dwarf (WD) companion. We study the effects of the strong dynamical interaction between the AGB wind and the WD and of photodissociation by the WD UV radiation o...
Article
Full-text available
High spectral resolution observations toward the low mass-loss rate C-rich, J-type asymptotic giant branch (AGB) star Y CVn were carried out at 7.5, 13.1, and 14.0 μm with the Echelon-cross-echelle Spectrograph mounted on the Stratospheric Observatory for Infrared Astronomy and the Texas Echelon-cross-echelle Spectrograph on the Infrared Telescope...
Preprint
We investigate the structure, dynamics, and chemistry of the molecule-rich nebula around the stellar symbiotic system R Aqr, which is significantly affected by the presence of a white dwarf (WD) companion. We study the effects of the strong dynamical interaction between the AGB wind and the WD and of photodissociation by the WD UV radiation on the...
Article
The atmospheres of synchronously rotating exoplanets are intrinsically three-dimensional, and fast vertical and horizontal winds are expected to mix the atmosphere, driving the chemical composition out of equilibrium. Due to the longer computation times associated with multi-dimensional forward models, horizontal mixing has only been investigated f...
Preprint
Full-text available
The atmospheres of synchronously rotating exoplanets are intrinsically three-dimensional, and fast vertical and horizontal winds are expected to mix the atmosphere, driving the chemical composition out of equilibrium. Due to the longer computation times associated with multi-dimensional forward models, horizontal mixing has only been investigated f...
Preprint
Full-text available
High spectral resolution observations toward the low mass-loss rate C-rich, J-type AGB star Y CVn have been carried out at 7.5, 13.1 and 14.0 um with SOFIA/EXES and IRTF/TEXES. Around 130 HCN and H13CN lines of bands v2, 2v2, 2v2-v2, 3v2-2v2, 3v2-v2, and 4v2-2v2 have been identified involving lower levels with energies up to ~3900 K. These lines ha...
Article
We report the detection of the oxygen-bearing complex organic molecules propenal (C 2 H 3 CHO), vinyl alcohol (C 2 H 3 OH), methyl formate (HCOOCH 3 ), and dimethyl ether (CH 3 OCH 3 ) toward the cyanopolyyne peak of the starless core TMC-1. These molecules were detected through several emission lines in a deep Q -band line survey of TMC-1 carried...
Article
Full-text available
We report the detection for the first time in space of three new pure hydrocarbon cycles in TMC-1: c -C 3 HCCH (ethynyl cyclopropenylidene), c -C 5 H 6 (cyclopentadiene), and c -C 9 H 8 (indene). We derive a column density of 3.1 × 10 ¹¹ cm ⁻² for the first cycle and similar values, in the range (1−2) × 10 ¹³ cm ⁻² , for the second and third. This...
Article
We report the first detection in space of the two doubly deuterated isotopologues of methyl acetylene. The species CHD 2 CCH and CH 2 DCCD were identified in the dense core L483 through, respectively, nine and eight rotational lines in the 72–116 GHz range using the 30 m telescope of the Institut de Radioastronomie Millimétrique (IRAM). We combined...
Preprint
Full-text available
We report the detection for the first time in space of three new pure hydrocarbon cycles in TMC-1: c-C3HCCH (ethynyl cyclopropenylidene), c-C5H6 (cyclopentadiene) and c-C9H8 (indene). We derive a column density of 3.1e11 cm-2 for the former cycle and similar values, in the range (1-2)e13 cm-2, for the two latter molecules. This means that cyclopent...