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  1. Article ; Online: History of two mass loss processes in VY CMa.

    Quintana-Lacaci, G / Velilla, L / Fonfría, J P / Cernicharo, J / Castro-Carrizo, A / Agúndez, M / Decin, L

    Proceedings of the International Astronomical Union. International Astronomical Union

    2023  Volume 669

    Abstract: Red Supergiant stars (RSGs) are known to eject large amounts of material 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 ...

    Abstract Red Supergiant stars (RSGs) are known to eject large amounts of material 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 have been proposed as responsible for this mass ejection including Alfvén waves, large convective cells, and magnetohydrodynamical (MHD) disturbances at the photosphere, but so far little is known about the actual processes taking place in these objects. Here we present high angular resolution interferometric ALMA maps of VY CMa continuum and molecular emission, which resolve the structure of the ejecta with unprecedented detail. We reconstructed the 3D structure of the gas traced by the different species. It allowed us to study the morphology and kinematics of the gas traced by the different species surrounding VY CMa. Two types of ejecta are clearly observed: extended, irregular, and vast ejecta surrounding the star that are carved by localized fast outflows. The structure of the outflows is found to be particularly flat. We present a 3D reconstruction of these outflows and proof of the carving. This indicates that two different mass loss processes take place in this massive star. We tentatively propose the physical cause for the formation of both types of structures. These results provide essential information on the mass loss processes of RSGs and thus of their further evolution.
    Language English
    Publishing date 2023-01-05
    Publishing country England
    Document type Journal Article
    ZDB-ID 2170724-8
    ISSN 1743-9221 ; 1743-9213
    ISSN (online) 1743-9221
    ISSN 1743-9213
    DOI 10.1051/0004-6361/202244396
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Atmospheric molecular blobs shape up circumstellar envelopes of AGB stars.

    Velilla-Prieto, L / Fonfría, J P / Agúndez, M / Castro-Carrizo, A / Guélin, M / Quintana-Lacaci, G / Cherchneff, I / Joblin, C / McCarthy, M C / Martín-Gago, J A / Cernicharo, J

    Nature

    2023  Volume 617, Issue 7962, Page(s) 696–700

    Abstract: During their thermally pulsing phase, asymptotic giant branch (AGB) stars eject material that forms extended dusty ... ...

    Abstract During their thermally pulsing phase, asymptotic giant branch (AGB) stars eject material that forms extended dusty envelopes
    Language English
    Publishing date 2023-05-17
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 120714-3
    ISSN 1476-4687 ; 0028-0836
    ISSN (online) 1476-4687
    ISSN 0028-0836
    DOI 10.1038/s41586-023-05917-9
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 26: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)
    Zs.MG 9: Show issues
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  3. Article: Gas infall and possible circumstellar rotation in R Leo.

    Fonfría, J P / Santander-García, M / Cernicharo, J / Velilla-Prieto, L / Agúndez, M / Marcelino, N / Quintana-Lacaci, G

    Astronomy and astrophysics

    2019  Volume 622

    Abstract: We present new interferometer molecular observations of R Leo taken at 1.2 mm with the Atacama Large Millimeter Array with an angular resolution up ... ...

    Abstract We present new interferometer molecular observations of R Leo taken at 1.2 mm with the Atacama Large Millimeter Array with an angular resolution up to
    Language English
    Publishing date 2019-02-25
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1458466-9
    ISSN 1432-0746 ; 0004-6361
    ISSN (online) 1432-0746
    ISSN 0004-6361
    DOI 10.1051/0004-6361/201834840
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article: Detection of vibrationally excited HC

    Pardo, J R / Bermúdez, C / Cabezas, C / Agúndez, M / Gallego, J D / Fonfría, J P / Velilla-Prieto, L / Quintana-Lacaci, G / Tercero, B / Guélin, M / Cernicharo, J

    Astronomy and astrophysics

    2020  Volume 640

    Abstract: Observations of IRC +10216 with the Yebes 40m telescope between 31 and 50 GHz have revealed more than 150 unidentified lines. Some of them can be grouped into a new series of 26 doublets, harmonically related with integer quantum numbers ranging ... ...

    Abstract Observations of IRC +10216 with the Yebes 40m telescope between 31 and 50 GHz have revealed more than 150 unidentified lines. Some of them can be grouped into a new series of 26 doublets, harmonically related with integer quantum numbers ranging from
    Language English
    Publishing date 2020-08-10
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1458466-9
    ISSN 1432-0746 ; 0004-6361
    ISSN (online) 1432-0746
    ISSN 0004-6361
    DOI 10.1051/0004-6361/202038571
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article: ALMA Observations of the Water Fountain Pre-Planetary Nebula IRAS 16342-3814: High-Velocity Bipolar Jets and an Expanding Torus.

    Sahai, R / Vlemmings, W H T / Gledhill, T / Sánchez Contreras, C / Lagadec, E / Nyman, L-Å / Quintana-Lacaci, G

    The astrophysical journal. Letters

    2017  Volume 835, Issue 1

    Abstract: ... We have ... ...

    Abstract We have mapped
    Language English
    Publishing date 2017-02-09
    Publishing country England
    Document type Journal Article
    ZDB-ID 2207648-7
    ISSN 2041-8205 ; 0004-637X
    ISSN 2041-8205 ; 0004-637X
    DOI 10.3847/2041-8213/835/1/L13
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: Clues to NaCN formation.

    Quintana-Lacaci, G / Cernicharo, J / Velilla Prieto, L / Agúndez, M / Castro-Carrizo, A / Fonfría, J P / Massalkhi, S / Pardo, J R

    Astronomy and astrophysics

    2017  Volume 607

    Abstract: Context: ALMA is providing us essential information on where certain molecules form. Observing where these molecules emission arises from, the physical conditions of the gas, and how this relates with the presence of other species allows us to ... ...

    Abstract Context: ALMA is providing us essential information on where certain molecules form. Observing where these molecules emission arises from, the physical conditions of the gas, and how this relates with the presence of other species allows us to understand the formation of many species, and to significantly improve our knowledge of the chemistry that occurs in the space.
    Aims: We studied the molecular distribution of NaCN around IRC +10216, a molecule detected previously, but whose origin is not clear. High angular resolution maps allow us to model the abundance distribution of this molecule and check suggested formation paths.
    Methods: We modeled the emission of NaCN assuming local thermal equilibrium (LTE) conditions. These profiles were fitted to azimuthal averaged intensity profiles to obtain an abundance distribution of NaCN.
    Results: We found that the presence of NaCN seems compatible with the presence of CN, probably as a result of the photodissociation of HCN, in the inner layers of the ejecta of IRC +10216. However, similar as for CH
    Language English
    Publishing date 2017-11-09
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1458466-9
    ISSN 1432-0746 ; 0004-6361
    ISSN (online) 1432-0746
    ISSN 0004-6361
    DOI 10.1051/0004-6361/201732015
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: Discovery of two new magnesium-bearing species in IRC+10216: MgC

    Cernicharo, J / Cabezas, C / Pardo, J R / Agúndez, M / Bermúdez, C / Velilla-Prieto, L / Tercero, F / López-Pérez, J A / Gallego, J D / Fonfría, J P / Quintana-Lacaci, G / Guélin, M / Endo, Y

    Astronomy and astrophysics

    2019  Volume 630

    Abstract: We report on the detection of two series of harmonically related doublets in IRC +10216. From the observed frequencies, the rotational constant of the first series ... ...

    Abstract We report on the detection of two series of harmonically related doublets in IRC +10216. From the observed frequencies, the rotational constant of the first series is
    Language English
    Publishing date 2019-09-23
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1458466-9
    ISSN 1432-0746 ; 0004-6361
    ISSN (online) 1432-0746
    ISSN 0004-6361
    DOI 10.1051/0004-6361/201936372
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article: Discovery of the first Ca-bearing molecule in space: CaNC.

    Cernicharo, J / Velilla-Prieto, L / Agúndez, M / Pardo, J R / Fonfría, J P / Quintana-Lacaci, G / Cabezas, C / Bermúdez, C / Guélin, M

    Astronomy and astrophysics

    2019  Volume 627

    Abstract: We report on the detection of calcium isocyanide, CaNC, in the carbon-rich evolved star IRC+10216. We derived a column density for this species of (2±0.5)× ... ...

    Abstract We report on the detection of calcium isocyanide, CaNC, in the carbon-rich evolved star IRC+10216. We derived a column density for this species of (2±0.5)×10
    Language English
    Publishing date 2019-07-03
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1458466-9
    ISSN 1432-0746 ; 0004-6361
    ISSN (online) 1432-0746
    ISSN 0004-6361
    DOI 10.1051/0004-6361/201936040
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article: A

    Quintana-Lacaci, G / Agúndez, M / Cernicharo, J / Bujarrabal, V / Sánchez Contreras, C / Castro-Carrizo, A / Alcolea, J

    Astronomy and astrophysics

    2016  Volume 592

    Abstract: Aims: Our knowledge of the chemical properties of the circumstellar ejecta of the most massive evolved stars is particularly poor. We aim to study the chemical characteristics of the prototypical yellow hypergiant star, IRC +10420. For this purpose, we ... ...

    Abstract Aims: Our knowledge of the chemical properties of the circumstellar ejecta of the most massive evolved stars is particularly poor. We aim to study the chemical characteristics of the prototypical yellow hypergiant star, IRC +10420. For this purpose, we obtained full line surveys at 1 and 3 mm atmospheric windows.
    Methods: We have identified 106 molecular emission lines from 22 molecular species. Approximately half of the molecules detected are N-bearing species, in particular HCN, HNC, CN, NO, NS, PN, and N
    Results: We have found that IRC +10420 presents high abundances of the N-bearing molecules compared with O-rich evolved stars. This result supports the presence of a N-rich chemistry, expected for massive stars. Our analysis also suggests a decrease of the
    Language English
    Publishing date 2016-07-22
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1458466-9
    ISSN 1432-0746 ; 0004-6361
    ISSN (online) 1432-0746
    ISSN 0004-6361
    DOI 10.1051/0004-6361/201527688
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article: IRC +10 216 in 3-D: morphology of a TP-AGB star envelope.

    Guélin, M / Patel, N A / Bremer, M / Cernicharo, J / Castro-Carrizo, A / Pety, J / Fonfría, J P / Agúndez, M / Santander-García, M / Quintana-Lacaci, G / Velilla Prieto, L / Blundell, R / Thaddeus, P

    Astronomy and astrophysics

    2018  Volume 610

    Abstract: During their late pulsating phase, AGB stars expel most of their mass in the form of massive dusty envelopes, an event that largely controls the composition of interstellar matter. The envelopes, however, are distant and opaque to visible and NIR ... ...

    Abstract During their late pulsating phase, AGB stars expel most of their mass in the form of massive dusty envelopes, an event that largely controls the composition of interstellar matter. The envelopes, however, are distant and opaque to visible and NIR radiation: their structure remains poorly known and the mass-loss process poorly understood. Millimeter-wave interferometry, which combines the advantages of longer wavelength, high angular resolution and very high spectral resolution is the optimal investigative tool for this purpose. Mm waves pass through dust with almost no attenuation. Their spectrum is rich in molecular lines and hosts the fundamental lines of the ubiquitous CO molecule, allowing a tomographic reconstruction of the envelope structure. The circumstellar envelope IRC +10 216 and its central star, the C-rich TP-AGB star closest to the Sun, are the best objects for such an investigation. Two years ago, we reported the first detailed study of the CO(2-1) line emission in that envelope, made with the IRAM 30-m telescope. It revealed a series of dense gas shells, expanding at a uniform radial velocity. The limited resolution of the telescope (HPBW 11″) did not allow us to resolve the shell structure. We now report much higher angular resolution observations of CO(2-1), CO(1-0), CN(2-1) and C
    Language English
    Publishing date 2018-02-07
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1458466-9
    ISSN 1432-0746 ; 0004-6361
    ISSN (online) 1432-0746
    ISSN 0004-6361
    DOI 10.1051/0004-6361/201731619
    Database MEDical Literature Analysis and Retrieval System OnLINE

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