Persona: Jimenez-Serra, Izaskun
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Centro de Astrobiologia
El Centro de Astrobiología (CAB) es un centro mixto de investigación en astrobiología, dependiente tanto del Instituto Nacional de Técnica Aeroespacial (INTA) como del Consejo Superior de Investigaciones Científicas (CSIC).
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Jimenez-Serra
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Izaskun
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Publicación Acceso Abierto Thiols in the Interstellar Medium: First Detection of HC(O)SH and Confirmation of C2H5SH(IOP Science Publishing, 2021-04-30) Rodríguez Almeida, L. F.; Jimenez-Serra, Izaskun; Rivilla, Victor M.; Martín Pintado, J.; Zeng, Shaoshan; Tercero, B.; De Vicente, P.; Colzi, Laura; Rico Villas, F.; Martín, S.; Requena Torres, Miguel Angel; Comunidad de Madrid; Agencia Estatal de Investigación (AEI); European Research Council (ERC); European Commission (EC); Rodríguez Almeida, L. F. [0000-0002-9785-703X]; Jiménez Serra, I. [0000-0003-4493-8714]; Rivilla, V. M. [0000-0002-2887-5859]; Martín Pintado, J. [0000-0003-4561-3508]; Tercero, B. [0000-0002-4782-5259]; Martín, S. [0000-0001-9281-2919]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737The chemical compounds carrying the thiol group (-SH) have been considered essential in recent prebiotic studies regarding the polymerization of amino acids. We have searched for this kind of compound toward the Galactic Center quiescent cloud G+0.693–0.027. We report the first detection in the interstellar space of the trans-isomer of monothioformic acid (t-HC(O)SH) with an abundance of ~1 × 10−10. Additionally, we provide a solid confirmation of the gauche isomer of ethyl mercaptan (g-C2H5SH) with an abundance of ~3 × 10−10, and we also detect methyl mercaptan (CH3SH) with an abundance of ~5 × 10−9. Abundance ratios were calculated for the three SH-bearing species and their OH analogs, revealing similar trends between alcohols and thiols with increasing complexity. Possible chemical routes for the interstellar synthesis of t-HC(O)SH, CH3SH, and C2H5SH are discussed, as well as the relevance of these compounds in the synthesis of prebiotic proteins in the primitive Earth.Publicación Acceso Abierto Expanding the C3H6O2 isomeric interstellar inventory: Discovery of lactaldehyde and methoxyacetaldehyde in G+0.693-0.027(EDP Sciences, 2026-02-23) Sanz-Novo, Miguel; Rivilla, Victor M.; Jimenez-Serra, Izaskun; Colzi, Laura; Zeng, Shaoshan; Megías, Andrés; San Andrés, David; López-Gallifa, Álvaro; Martínez-Henares, Antonio; Fried, Zachary; McGuire, Brett; Martin Ruiz, Sergio; Requena Torres, Miguel Angel; Tercero, Belén; de Vicente, Pablo; Kolesniková, Lucie; Alonso, Elena Rita; Cocinero, E. J.; Guillemin, Jean-Claude; Kleiner, I.; Agencia Estatal de Investigación (España); Comunidad de Madrid; Centre National D'Etudes Spatiales (CNES); Consejo Superior de Investigaciones Científicas (CSIC); Gobierno Vasco; Instituto Geográfico Español (IGN); European Commission (EC); Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737Aims. The tentative detection of 3-hydroxypropanal (HO(CH2)2C(O)H) toward the Galactic center molecular cloud G+0.693-0.027 prompts a systematic survey in this source aimed at detecting all C3H6O2 isomers with available spectroscopy. Methods. We used an ultra-deep broadband spectral survey of G+0.693-0.027, carried out with the Yebes 40 m and IRAM 30 m telescopes, to conduct the astronomical search. Results. We report the first interstellar detection of lactaldehyde (CH3CH(OH)C(O)H) and methoxyacetaldehyde (CH3OCH2C(O)H), together with the second detections (i.e., confirmation) of methyl acetate (CH3C(O)OCH3) and hydroxyacetone (CH3C(O)CH2OH), and new detections in this source of both anti - and g auche - conformers of ethyl formate (CH3CH2OC(O)H; the latter being tentative). For these species, we derived a fractional abundance relative to H2 of ~(0.81, 0.24, 16, 1.6, 1.3, 1.4) × 10−10, respectively. In contrast, neither propionic acid, CH3CH2C(O)OH, nor glycidol, c-CH2OCHCH2OH (i.e., the most and the least stable species within the C3H6O2 family, respectively) were detected, and we provide upper limits on their fractional abundances of ≤1.5 × 10−10 and ≤3.7 × 10−11. Interestingly, all C3H6O2 isomers can be synthesized through radical-radical reactions on the surface of dust grains, ultimately tracing back to CO as the parent molecule. We suggest that formation of the detected isomers is mainly driven by successive hydrogenation of CO, producing CH3OH and CH3CH2OH as the primary parent species. Conversely, propionic acid is thought to originate from the oxygenation of CO via the HOCO intermediate, which help us rationalize its non-detection. Overall, our findings notably expand the known chemical inventory of the interstellar medium and provide direct observational evidence that increasingly complex chemistry involving O-bearing species occurs in space.Publicación Acceso Abierto Synthesis and Spectroscopic Characterization of Interstellar Candidate Ethynyl Thiocyanate: HCCSCN(IOP Publishing, 2024-11-14) Alonso, Elena Rita; Insausti, Aran; Kolesniková, Lucie; León, Iker; McGuire, Brett A.; Shingledecker, Christopher N.; Agúndez, Marcelino ; Cernicharo, José; Rivilla, Victor M.; Cabezas, Carlos ; Jimenez-Serra, Izaskun; Martín-Pintado, Jesús; Guillemin, Jean Claude; National Science Foundation (NSF); Junta de Castilla y León; European Commission (EC); El Consejo Superior de Investigaciones Científicas (CSIC); Centre National de la Recherche Scientifique (CNRS); Ministerio de Ciencia e Innovación (MICINN)This work aims to spectroscopically characterize and provide for the first time direct experimental frequencies of the ground vibrational state and two excited states of the simplest alkynyl thiocyanate (HCCSCN) for astrophysical use. Both microwave (8-16 GHz) and millimeter-wave regions (50-120 GHz) of the spectrum have been measured and analyzed in terms of Watson’s semirigid rotor Hamiltonian. A total of 314 transitions were assigned to the ground state of HCCSCN, and a first set of spectroscopic constants have been accurately determined. Spectral features of the molecule were then searched for in Sgr B2(N), NGC 6334I, G+0.693−0.027, and TMC-1 molecular clouds. Upper limits to the column density are provided.Publicación Acceso Abierto A chemical study of carbon fractionation in external galaxies(Oxford Academics: Blackwell Publishing, 2020-07-18) Viti, S.; Fontani, F.; Jimenez-Serra, Izaskun; Agencia Estatal de Investigación (AEI); European Research Council (ERC); Science and Technology Facilities Council (STFC); 0000-0003-4493-8714; 0000-0003-0348-3418; 0000-0001-8504-8844; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737In the interstellar medium carbon exists in the form of two stable isotopes 12C and 13C and their ratio is a good indicator of nucleosynthesis in galaxies. However, chemical fractionation can potentially significantly alter this ratio and in fact observations of carbon fractionation within the same galaxy has been found to vary from species to species. In this paper, we theoretically investigate the carbon fractionation for selected abundant carbon-bearing species in order to determine the conditions that may lead to a spread of the 12C/13C ratio in external galaxies. We find that carbon fractionation is sensitive to almost all the physical conditions we investigated, it strongly varies with time for all species but CO, and shows pronounced differences across species. Finally, we discuss our theoretical results in the context of the few observations of the 12C/13C in both local and higher redshift galaxies.Publicación Restringido Detection of the elusive dangling OH ice features at ~2.7 μm in Chamaeleon I with JWST NIRCam(Nature Publishing Group, 2024-09-01) Noble, Jennifer; Fraser, Helen; Smith, Z. L.; Dartois, E.; Boogert, A. C. A.; Cuppen, Herma; Dickinson, Hugh J.; Dulieu, F.; Egami, E.; Erkal, Jessica; Giuliano, B. M.; Husquinet, Basile; Lamberts, T.; Maté, B.; McClure, Melissa; Palumbo, M. E.; Shimonishi, T.; Sun, F.; Bergner, Jennifer; Brown, Wendy; Caselli, P.; Congiu, E.; Drozdovskaya, Maria Nikolayevna; Herrero, V. J.; Ioppolo, Sergio; Jimenez-Serra, Izaskun; Linnartz, Harold; Melnick, G. J.; McGuire, Brett; Oberg, Karin; Perotti, G.; Qasim, D.; Rocha, Will Robson Monteiro; Urso, Riccardo GiovanniAscertaining the morphology and composition of the icy mantles covering dust grains in dense, cold regions of the interstellar medium is essential to developing accurate astrochemical models, determining conditions for ice formation, constraining chemical interactions in and on icy grains and understanding how ices withstand space radiation. The widely observed infrared spectroscopic signature of H2O ice at ~3 μm discriminates crystalline from amorphous structures in interstellar ices. Weaker bands seen only in laboratory ice spectra at ~2.7 μm, termed ‘dangling OH’ (dOH), are attributed to water molecules not fully bound to neighbouring water molecules and are often considered as tracing the degree of ice compaction. We exploit the high sensitivity of JWST NIRCam to detect two dOH features at 2.703 and 2.753 μm along multiple lines of sight probing the dense cloud Chamaeleon I, attributing these signatures to unbound dOH in cold water ice and dOH in interaction with other molecular species. These detections open a path to using the dOH features as tracers of the formation, composition, morphology and evolution of icy grains during the star and planet formation process.Publicación Acceso Abierto ALMA–IRDC: dense gas mass distribution from cloud to core scales(Oxford Academics: Oxford University Press, 2021-03-22) Barnes, A. T.; Henshaw, J. D.; Fontani, F.; Pineda, Jaime E.; Cosentino, G.; Tan, J. C.; Caselli, P.; Wang, K.; Jimenez-Serra, Izaskun; Law, C. Y.; Avison, A.; Bigiel, F.; Feng, S.; Kong, S.; Longmore, Steven N.; Moser, L.; Parker, R. J.; Sánchez Monge, Álvaro ; European Research Council (ERC); Agencia Estatal de Investigación (AEI); Deutsche Forschungsgemeinschaft (DFG); East Asia Core Observatories Association (EACOA); National Natural Science Foundation of China (NSFC); National Key Research and Development Program of China; Peking University; Avison, A. [0000-0002-2562-8609]Infrared dark clouds (IRDCs) are potential hosts of the elusive early phases of high mass star formation (HMSF). Here, we conduct an in-depth analysis of the fragmentation properties of a sample of 10 IRDCs, which have been highlighted as some of the best candidates to study HMSF within the Milky Way. To do so, we have obtained a set of large mosaics covering these IRDCs with Atacama Large Millimeter/submillimeter Array (ALMA) at Band 3 (or 3 mm). These observations have a high angular resolution (∼3 arcsec; ∼0.05 pc), and high continuum and spectral line sensitivity (∼0.15 mJy beam−1 and ∼0.2 K per 0.1 km s−1 channel at the N2H+ (1 − 0) transition). From the dust continuum emission, we identify 96 cores ranging from low to high mass (M = 3.4−50.9 M⊙) that are gravitationally bound (αvir = 0.3−1.3) and which would require magnetic field strengths of B = 0.3−1.0 mG to be in virial equilibrium. We combine these results with a homogenized catalogue of literature cores to recover the hierarchical structure within these clouds over four orders of magnitude in spatial scale (0.01–10 pc). Using supplementary observations at an even higher angular resolution, we find that the smallest fragments (<0.02 pc) within this hierarchy do not currently have the mass and/or the density required to form high-mass stars. None the less, the new ALMA observations presented in this paper have facilitated the identification of 19 (6 quiescent and 13 star-forming) cores that retain >16 M⊙ without further fragmentation. These high-mass cores contain trans-sonic non-thermal motions, are kinematically sub-virial, and require moderate magnetic field strengths for support against collapse. The identification of these potential sites of HMSF represents a key step in allowing us to test the predictions from high-mass star and cluster formation theories.Publicación Acceso Abierto Vibrationally excited HC3N emission in NGC 1068: tracing the recent star formation in the starburst ring(Oxford Academics: Oxford University Press, 2021-01-25) Rico Villas, F.; Martín Pintado, J.; González Alfonso, E.; Rivilla, Victor M.; Martín, S.; García Burillo, S.; Jimenez-Serra, Izaskun; Sánchez García, M.; Agencia Estatal de Investigación (AEI); European Research Council (ERC); Rivilla, V. M. [0000-0002-2887-5859]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737Using the ALMA data, we have studied the HC3N and continuum emission in the starburst pseudo-ring (SB pseudo-ring) and the circumnuclear disc (CND) of the SB/active galactic nucleus (AGN) composite galaxy NGC 1068. We have detected emission from vibrationally excited HC3N (HC3N*) only towards one star-forming region of the SB pseudo-ring. Remarkably, HC3N* was not detected towards the CND despite its large HC3N v = 0 column density. From local thermodynamic equilibrium (LTE) and non-LTE modelling of HC3N*, we obtained a dust temperature (Tdust) of ∼250 K and a density (nH2) of 6×105 cm−3 for this star-forming region. The estimated infrared (IR) luminosity of 5.8 × 108 L⊙ is typical of proto-superstar clusters (proto-SSCs) observed in the SB galaxy NGC 253. We use the continuum emissions at 147 and 350 GHz, along with CO and Pa α, to estimate the ages of other 14 SSCs in the SB pseudo-ring. We find the SSCs to be associated with the region connecting the nuclear bar with the SB pseudo-ring, supporting the inflow scenario. For the CND, our analysis yields Tdust ≤ 100 K and nH2∼(3−6)×105 cm−3. The very different dust temperatures found for the CND and the proto-SSC indicate that, while the dust in the proto-SSC is being efficiently heated from the inside by the radiation from massive protostars, the CND is being heated externally by the AGN, which in the IR optically thin case can only heat the dust to 56 K. We discuss the implications of the non-detection of HC3N* near the luminous AGN in NGC 1068 on the interpretation of the HC3N* emission observed in the SB/AGN composite galaxies NGC 4418 and Arp 220.Publicación Acceso Abierto FAUST I. The hot corino at the heart of the prototypical Class I protostar L1551 IRS5.(Oxford Academics: Oxford University Press, 2020-07-21) Bianchi, S.; Chandler, C. J.; Ceccarelli, C.; Codella, C.; Sakai, N.; López Sepulcre, A.; Maud, L. T.; Moellenbrock, G.; Svoboda, B.; Watanabe, Y.; Sakai, T.; Ménard, F.; Aikawa, Y.; Alves, F.; Balucani, N.; Bouvier, M.; Caselli, P.; Caux, E.; Charnley, S.; Choudhury, S.; De Simone, M.; Dulieu, F.; Durán, A.; Evans, L.; Favre, C.; Fedele, D.; Feng, S.; Fontani, F.; Francis, L.; Hama, T.; Hanawa, T.; Herbst, E.; Hirota, T.; Imai, M.; Isella, A.; Jimenez-Serra, Izaskun; Johnstone, D.; Kahane, C.; Lefloch, B.; Loinard, L.; Maureira, M. J.; Mercimek, S.; Miotello, A.; Mori, S.; Nakatani, R.; Nomura, H.; Oba, Y.; Ohashi, S.; Okoda, Y.; Ospina Zamudio, J.; Oya, Y.; Pineda, Jaime E.; Podio, L.; Rimola, A.; Segura Cox, D.; Shirley, Y.; Taquet, V.; Testi, L.; Vastel, C.; Viti, S.; Watanabe, N.; Witzel, A.; Xue, C.; Zhao, B.; Zhang, Y.; Yamamoto, S.; European Research Council (ERC); Japan Society for the Promotion of Science (KAKENHI); Agencia Estatal de Investigación (AEI); Universidad Nacional Autónoma de México (UNAM); Agence Nationale de la Recherche (ANR); Balucani, N. [0000-0001-5121-5683]; De Oliveira Alves, F. [0000-0002-7945-064X]; Hama, T. [0000-0002-4991-4044]; Ohashi, S. [0000-0002-9661-7958]; Johnstone, D. [0000-0002-6773-459X]; Watanabe, Y. [0000-0002-9668-3592]; Ceccarelli, C. [0000-0001-9664-6292]; Pineda, J. [0000-0002-3972-1978]; Fedele, D. [0000-0001-6156-0034]; Mercimek, S. [0000-0002-0742-7934]; Xue, C. [0000-0003-2760-2119]; Sakai, N. [0000-0002-3297-4497]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737The study of hot corinos in solar-like protostars has been so far mostly limited to the Class 0 phase, hampering our understanding of their origin and evolution. In addition, recent evidence suggests that planet formation starts already during Class I phase, which therefore represents a crucial step in the future planetary system chemical composition. Hence, the study of hot corinos in Class I protostars has become of paramount importance. Here, we report the discovery of a hot corino towards the prototypical Class I protostar L1551 IRS5, obtained within the ALMA (Atacama Large Millimeter/submillimeter Array) Large Program FAUST (Fifty AU STudy of the chemistry in the disc/envelope system of solar-like protostars). We detected several lines from methanol and its isotopologues (13CH3OH and CH2DOH), methyl formate, and ethanol. Lines are bright towards the north component of the IRS5 binary system, and a possible second hot corino may be associated with the south component. The methanol lines' non-LTE analysis constrains the gas temperature (∼100 K), density (≥1.5 × 108 cm−3), and emitting size (∼10 au in radius). All CH3OH and 13CH3OH lines are optically thick, preventing a reliable measure of the deuteration. The methyl formate and ethanol relative abundances are compatible with those measured in Class 0 hot corinos. Thus, based on this work, little chemical evolution from Class 0 to I hot corinos occurs.Publicación Acceso Abierto 2-aminooxazole in Astrophysical Environments: IR Spectra and Destruction Cross Sections for Energetic Processing(IOP Science Publishing, 2021-03-11) Maté, B.; Carrasco Herrera, R.; Timón, V.; Tanarro, I.; Herrero, V. J.; Carrascosa, H. ; Muñoz Caro, G. M.; González Díaz, Cristobal; Jimenez-Serra, Izaskun; Agencia Estatal de Investigación (AEI); 0000-0002-5478-8644; 0000-0002-1217-6834; 0000-0002-1888-513X; 0000-0002-7456-4832; 0000-0002-2885-4847; 0000-0001-7003-7368; 0000-0002-8789-9148; 0000-0003-4493-8714; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-07372-aminooxazole (2AO), a N-heterocyclic molecule, has been proposed as an intermediate in prebiotic syntheses. It has been demonstrated that it can be synthesized from small molecules such as cyanamide and glycoaldehyde, which are present in interstellar space. The aim of this work is to provide infrared (IR) spectra, in the solid phase for conditions typical of astrophysical environments and to estimate its stability toward UV photons and cosmic rays. IR (4000–600 cm−1) absorption spectra at 20 K, 180 K, and 300 K, IR band strengths, and room-temperature UV (120–250 nm) absorption spectra are given for the first time for this species. Destruction cross sections of ≈9.5 10−18 cm2 and ≈2 10−16 cm2 were found in the irradiation at 20 K of pure 2AO and 2AO:H2O ices with UV (6.3–10.9 eV) photons or 5 keV electrons, respectively. These data were used to estimate half-life times for the molecule in different environments. It is estimated that 2AO could survive UV radiation and cosmic rays in the ice mantles of dense clouds beyond cloud collapse. In contrast, it would be very unstable on the surface of cold solar system bodies like Kuiper Belt objects, but the molecule could still survive within dust grain agglomerates or cometesimals.Publicación Acceso Abierto ALMA–IRDC – II. First high-angular resolution measurements of the 14N/15N ratio in a large sample of infrared-dark cloud cores(Oxford Academics: Oxford University Press, 2021-03-22) Fontani, F.; Barnes, A. T.; Caselli, P.; Henshaw, J. D.; Cosentino, G.; Jimenez-Serra, Izaskun; Tan, J. C.; Pineda, Jaime E.; Law, C. Y.; European Research Council (ERC); Agencia Estatal de Investigación (AEI)The 14N/15N ratio in molecules exhibits a large variation in star-forming regions, especially when measured from N2H+ isotopologues. However, there are only a few studies performed at high-angular resolution. We present the first interferometric survey of the 14N/15N ratio in N2H+ obtained with Atacama Large Millimeter Array observations towards four infrared-dark clouds harbouring 3 mm continuum cores associated with different physical properties. We detect N15NH+ (1–0) in ∼20−40 per cent of the cores, depending on the host cloud. The 14N/15N values measured towards the millimetre continuum cores range from a minimum of ∼80 up to a maximum of ∼400. The spread of values is narrower than that found in any previous single-dish survey of high-mass star-forming regions and than that obtained using the total power data only. This suggests that the 14N/15N ratio is on average higher in the diffuse gaseous envelope of the cores and stresses the need for high-angular resolution maps to measure correctly the 14N/15N ratio in dense cores embedded in IRDCs. The average 14N/15N ratio of ∼210 is also lower than the interstellar value at the Galactocentric distance of the clouds (∼300–330), although the sensitivity of our observations does not allow us to unveil 14N/15N ratios higher than ∼400. No clear trend is found between the 14N/15N ratio and the core physical properties. We find only a tentative positive trend between 14N/15N and H2 column density. However, firmer conclusions can be drawn only with higher sensitivity measurements.
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