- A cosmic matter clump asking himself about life, Universe and beyond... and trying to live, love, and learn through his journey.edit
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Magnetic fields are likely to be an efficient mechanism which can affect evolved intermediate mass stars (i.e. post-AGB stars and planetary nebulae) in different ways such as via the shaping of their envelope. However, observational... more
Magnetic fields are likely to be an efficient mechanism which can affect evolved intermediate mass stars (i.e. post-AGB stars and planetary nebulae) in different ways such as via the shaping of their envelope. However, observational probes for the presence of those fields are still scarce. I will present a summary of the works, including those from our group, on the detection and measurement of magnetic fields in various evolved objects.
We present studies using different observational techniques, along different frequencies, aiming to resolve and investigate jets, outflows, as well as compact and innermost regions of asymmetric planetary nebulae (PNe) and objects in... more
We present studies using different observational techniques, along different frequencies, aiming to resolve and investigate jets, outflows, as well as compact and innermost regions of asymmetric planetary nebulae (PNe) and objects in transition to PN. All the information gathered allow us to explore the kinematics and other important properties of the structures that play a crucial role in the shaping of complex PNe morphologies, in particular, we explore the role of disks/tori as collimating engine of extreme axisymmetric PNe.
In this paper, we determine the habitability of Sun-like stars in the Galaxy using Monte Carlo simulations, which are guided by the factors of the Drake Equation for the considerations on the astrophysical and biological parameters needed... more
In this paper, we determine the habitability of Sun-like stars in the Galaxy using Monte Carlo simulations, which are guided by the factors of the Drake Equation for the considerations on the astrophysical and biological parameters needed to generate and maintain life on a planet's surface. We used a simple star distribution, initial mass function and star formation history to reproduce the properties and distribution of stars within the Galaxy. Using updated exoplanet data from the Kepler mission, we assign planets to some of the stars, and then follow the evolution of life on the planets that met the habitability criteria using two different civilization hypotheses. We predict that around 51% of Earth-like planets in the habitable zone (HZ) are inhabited by primitive life and 4% by technological life. We apply the results to the Kepler field of view, and predicted that there should be at least six Earth-like planets in the HZ, three of them inhabited by primitive life. Accordi...
Research Interests: Geology and Astrobiology
We present an observational study of three oint-ymmetric lanetary ebulae (PS-PNe): PC 19, He 2-429, and He 1-1, whose kinematics has been previously reported in the literature. The study includes an analysis of physical conditions and... more
We present an observational study of three oint-ymmetric lanetary ebulae (PS-PNe): PC 19, He 2-429, and He 1-1, whose kinematics has been previously reported in the literature. The study includes an analysis of physical conditions and chemical abundances. We found that the abundances of He 2-429 and He 1-1 correspond to a Peimbert Type I PNe while those of PC 19 are in good agreement with a Type IV PN. Kinematic evidence derived from proper motion measurement support PC 19 classification and suggest that the progenitor star was a low-mass low-metallicity member of the galactic halo population.
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Narrow band images, low and high dispersion long slit spectra and radio continuum data of the planetary nebula NGC 6445 are presented. Spectra were obtained with the 2.1m UNAM Telescope at San Pedro Martir Observatory (OAN-SPM, Mexico)... more
Narrow band images, low and high dispersion long slit spectra and radio continuum data of the planetary nebula NGC 6445 are presented. Spectra were obtained with the 2.1m UNAM Telescope at San Pedro Martir Observatory (OAN-SPM, Mexico) using the Boller & Chivens spectrograph and the Manchester Echelle Spectrograph. CCD imagery was obtained with the 1.5 m Telescope at Observatorio de
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Narrow band CCD images and low and high dispersion longslit spectra from the planetary nebula NGC 6445 are presented. This is a non-symmetric type I bipolar nebula with a very bright central ring, opened lobes, and remarkable features.... more
Narrow band CCD images and low and high dispersion longslit spectra from the planetary nebula NGC 6445 are presented. This is a non-symmetric type I bipolar nebula with a very bright central ring, opened lobes, and remarkable features. Using high dispersion spectra we obtain the kinematical structure of NGC 6445 and some of its internal knots. Low dispersion spectra have
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In order to investigate the characteristics and influence of the magnetic field in evolved stars, we performed a follow-up investigation of our previous submillimeter analysis of the proto-planetary nebula (PPN) OH 231.8+4.2 (Sabin et al.... more
In order to investigate the characteristics and influence of the magnetic field in evolved stars, we performed a follow-up investigation of our previous submillimeter analysis of the proto-planetary nebula (PPN) OH 231.8+4.2 (Sabin et al. 2014), this time at 1.3mm with the CARMA facility in polarisation mode for the purpose of a multi-scale analysis. OH 231.8+4.2 was observed at ~2.5" resolution and we detected polarised emission above the 3-sigma threshold (with a mean polarisation fraction of 3.5 %). The polarisation map indicates an overall organised magnetic field within the nebula. The main finding in this paper is the presence of a structure mostly compatible with an ordered toroidal component that is aligned with the PPN's dark lane. We also present some alternative magnetic field configuration to explain the structure observed. These data complete our previous SMA submillimeter data for a better investigation and understanding of the magnetic field structure in OH 2...
Presentamos los parámetros fundamentales de enrojecimiento, metalicidad, edad y distancia de los cúmulos abiertos poco estudiados Be 89, Ru 135 y Be 10, derivados de la fotometría CCD UBVRI. Los enrojecimientos interestelares se midieron... more
Presentamos los parámetros fundamentales de enrojecimiento, metalicidad, edad y distancia de los cúmulos abiertos poco estudiados Be 89, Ru 135 y Be 10, derivados de la fotometría CCD UBVRI. Los enrojecimientos interestelares se midieron en el diagrama color-color, y las metalicidades fotométricas se derivaron del exceso de ultravioleta de las estrellas tipo F. Las distancias y edades se obtuvieron ajustando isocronas a las secuencias observadas en cinco diagramas colormagnitud diferentes. Los promedios ponderados de los módulos de distancia y distancias heliocéntricas [(V0 ¿ MV ), d(kpc)] son: (11.m 90 ± 0.m 06, 2.4 ± 0.06) para Be 89, (9.m 58 ± 0.m 07, 0.81 ± 0.03) para Ru 135 y (11.m 16 ± 0.m 06, 1.7 ± 0.05) para Be 10, mientras que los promedios ponderados para las edades [log(A),A(Gyr)] son: (9.58 ± 0.06, 3.8 ± 0.6) para Be 89, (9.58 ± 0.06, 3.8 ± 0.7) para Ru 135 y (9.06 ± 0.05, 1.08 ± 0.08) para Be 10.
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Once classified as an emission line source, the planetary nebula (PN) nature of the source Kn 26 has been only recently recognized in digital sky surveys. To investigate the spectral properties and spatio-kinematical structure of Kn 26,... more
Once classified as an emission line source, the planetary nebula (PN) nature of the source Kn 26 has been only recently recognized in digital sky surveys. To investigate the spectral properties and spatio-kinematical structure of Kn 26, we have obtained high spatial-resolution optical and near-IR narrow-band images, high-dispersion long-slit echelle spectra, and intermediate-resolution spectroscopic observations. The new data reveal an hourglass morphology typical of bipolar PNe. A detailed analysis of its morphology and kinematics discloses the presence of a second pair of bipolar lobes, making Kn 26 a new member of the subclass of quadrupolar PNe. The time-lap between the ejection of the two pairs of bipolar lobes is much smaller than their dynamical ages, implying a rapid change of the preferential direction of the central engine. The chemical composition of Kn 26 is particularly unusual among PNe, with a low N/O ratio (as of type II PNe) and a high helium abundance (as of type I...
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We present new narrow-band Ha, [N II], and [O III] high-resolution images of the quadrupolar planetary nebula (PN) NGC 6309 that show in great detail its bipolar lobes and reveal new morphological features. New high- and low-dispersion... more
We present new narrow-band Ha, [N II], and [O III] high-resolution images of the quadrupolar planetary nebula (PN) NGC 6309 that show in great detail its bipolar lobes and reveal new morphological features. New high- and low-dispersion long-slit spectra have been obtained to help in the investigation of the new nebular components. The images and spectra unveil two diffuse blobs, one of them located at 55 arcsec from the central star along the NE direction (PA= +71) and the other at 78 arcsec in the SW direction (PA= -151). Therefore, these structures do not share the symmetry axes of the inner bipolar outflows. Their radial velocities relative to the system are quite low: +3 and -4 km/s, respectively. Spectroscopic data confirm a high [O III] to Ha ratio, indicating that the blobs are being excited by the UV flux from the central star. Our images convincingly show a spherical halo 60 arcsec in diameter encircling the quadrupolar nebula. The expansion velocity of this shell is low, 6...
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ABSTRACT A spectacular (314 4) bipolar nebula, with a symmetric and rotating, high-velocity collimated outffow, with episodic outburst properties, has been discovered in the Cassiopeia-Cepheus region. A compact object classified as the... more
ABSTRACT A spectacular (314 4) bipolar nebula, with a symmetric and rotating, high-velocity collimated outffow, with episodic outburst properties, has been discovered in the Cassiopeia-Cepheus region. A compact object classified as the planetary nebula KjPn 8 ...
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For over four decades, physical parameters such as electron density, total ionized mass, and emission measure from H II regions, have been derived using radio continuum observations applying the formalism by Mezger & Henderson... more
For over four decades, physical parameters such as electron density, total ionized mass, and emission measure from H II regions, have been derived using radio continuum observations applying the formalism by Mezger & Henderson (1967, Astrophysical Journal, 147, 471), which assumes filled sphere, cylinder, and gaussian models. These models are good approximations when applied to H II regions. However, in
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ABSTRACT Point-Symmetric Planetary Nebulae (PSPNe) are an important part in morphological classification as they exhibit features (e.g. collimated jets, knots) that can directly be associated to physical processes such as precession,... more
ABSTRACT Point-Symmetric Planetary Nebulae (PSPNe) are an important part in morphological classification as they exhibit features (e.g. collimated jets, knots) that can directly be associated to physical processes such as precession, binarity or magnetic action. This connection seems more obvious than when it comes to bipolar Planetary Nebulae (PNe) for example, and PSPNe have often been referred to as a proper class. We present a cross-analysis of a group of PSPNe as well as a more detailed physical and kinematical analysis of three cases displaying what we consider to be different type of point-symmetry. The combination of the high resolution spectroscopy with the morpho-kinematical tool Shape is giving new insights in the understanding of those complex structures.
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ABSTRACT Narrow-band Hα, [NII] λ6583, and [OIII] λ5007 images of Kn 26 were acquired on June 21, 2009 using ALFOSC (Andalucia Faint Object Spectrograph and Camera) at the 2.56m Nordic Optical Telescope (NOT) of the Observatorio de Roque... more
ABSTRACT Narrow-band Hα, [NII] λ6583, and [OIII] λ5007 images of Kn 26 were acquired on June 21, 2009 using ALFOSC (Andalucia Faint Object Spectrograph and Camera) at the 2.56m Nordic Optical Telescope (NOT) of the Observatorio de Roque de los Muchachos (ORM, La Palma, Spain). Narrow-band H2 2.1218um, Brγ 2.1658um, and K continuum at 2.270um images of Kn 26 were obtained on June 27, 2010 using LIRIS at the Cassegrain focus of the 4.2m William Herschel Telescope (WHT) at the ORM. Intermediate-resolution long-slit spectra of Kn 26 were obtained on October 5, 2011 using the ALBIREO spectrograph at the 1.5m telescope of the Observatorio de Sierra Nevada (OSN), Granada, Spain. Long-slit high-dispersion spectroscopy on the Hα and [NII] λ6583 lines of Kn 26 has been acquired on June 13, 2010 using the Manchester Echelle Spectrometer (MES) mounted on the 2.1m (f/7.5) telescope at the Observatorio Astronomico Nacional de San Pedro Martir (OAN-SPM, Mexico). (2 data files).
ABSTRACT The role of magnetic fields in late type stars and their nebulae, such as proto-planetary (PPNe) and planetary nebulae (PNe), is poorly known from an observational point of view. We therefore present new submillimeter... more
ABSTRACT The role of magnetic fields in late type stars and their nebulae, such as proto-planetary (PPNe) and planetary nebulae (PNe), is poorly known from an observational point of view. We therefore present new submillimeter observations realised with the Sub-Millimeter Array (SMA) which unveil the dust continuum polarisation in two well known PPNe: CRL 618 and OH 231.8+4.2. Assuming the current grain alignment theory, we also trace the geometry of the magnetic field in these two objects. The combination of this study with previous submillimeter observations, done with SCUBA at JCMT, will then pave the way for a better understanding of the evolution of magnetic fields in the envelopes of PPNe and PNe.
ABSTRACT We present new high resolution narrow-band [OIII] λ5007 images, as well as long-slit high resolution echelle spectra of the planetary nebula NGC 6309 at unprecedented detail, comfirming the presence of a halo circumscribing the... more
ABSTRACT We present new high resolution narrow-band [OIII] λ5007 images, as well as long-slit high resolution echelle spectra of the planetary nebula NGC 6309 at unprecedented detail, comfirming the presence of a halo circumscribing the quadrupolar outflows and discovering two diffuse emission blobs, which seem to be related to collimated ejections from the central star. Radial velocities of these faint blobs are very low, but qualitatively correspond to the radial direction of the quadrupolar lobes. Some possible scenarios are discussed, including collimated outflows from the central star and interaction of wind with field material, among others.
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Deriving physical conditions and chemical abundances of an ionized nebula involves a sequence of simple but large amount of calculations. ANNEB is a software developed to help in those calculations and to get a proper approach to... more
Deriving physical conditions and chemical abundances of an ionized nebula involves a sequence of simple but large amount of calculations. ANNEB is a software developed to help in those calculations and to get a proper approach to uncertainties in all derived quantities.
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ABSTRACT It has been suggested that the presence of disks or tori around the central stars of pre Planetary Nebulae and Planetary Nebulae is related to the collimation of the jet that are frequently observed in these sources. These disks... more
ABSTRACT It has been suggested that the presence of disks or tori around the central stars of pre Planetary Nebulae and Planetary Nebulae is related to the collimation of the jet that are frequently observed in these sources. These disks or tori can be traced by the maser emission of some molecules such as water. In this work we present Very Large Array (VLA) observations of the water maser emission at 22 GHz toward the PN IRAS 18061-2505, for which the masers appear located on one side of the central star. For comparison with the observations, we present a simple kinematical model of a disk rotating and expanding around the central star. The model matches qualitatively the observations. However, since the masers appear only on one side of the disk, these results are not conclusive.
The CCD UBV(RI)C observations of this paper have been made exclusively with the 0.84-m f/15 Ritchey-Chretien telescope at SPM, during the night of 2001 June 25/26 for the open cluster Be 80, and the nights 2002 February 6/7 and 8/9 for... more
The CCD UBV(RI)C observations of this paper have been made exclusively with the 0.84-m f/15 Ritchey-Chretien telescope at SPM, during the night of 2001 June 25/26 for the open cluster Be 80, and the nights 2002 February 6/7 and 8/9 for the clusters NGC 2192 and Be 15, respectively. (3 data files).
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ABSTRACT Kn 26 is a recently identified planetary nebula (PN). To confirm its nature and study its spatio-kinematical structure, we have obtained high spatial-resolution optical and near-IR narrowband images, high-dispersion long-slit... more
ABSTRACT Kn 26 is a recently identified planetary nebula (PN). To confirm its nature and study its spatio-kinematical structure, we have obtained high spatial-resolution optical and near-IR narrowband images, high-dispersion long-slit echelle spectra, and intermediate-resolution spectroscopic observations. The new data confirm the PN nature of Kn 26 and reveal features typical of bipolar PNe: hourglass morphology, H2 emission, and nitrogen enrichment. A detailed analysis of its morphology and kinematics, however, suggests the presence of one additional pair of bipolar lobes that would make Kn 26 a new member of the class of quadrupolar PNe.
Narrow band CCD images and low and high dispersion longslit spectra from the planetary nebula NGC 6445 are presented. This is a non-symmetric type I bipolar nebula with a very bright central ring, opened lobes, and remarkable features.... more
Narrow band CCD images and low and high dispersion longslit spectra from the planetary nebula NGC 6445 are presented. This is a non-symmetric type I bipolar nebula with a very bright central ring, opened lobes, and remarkable features. Using high dispersion spectra we obtain the kinematical structure of NGC 6445 and some of its internal knots. Low dispersion spectra have
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We have studied the internal kinematics and physical conditions throughout the planetary nebula NGC 2371. Narrow-band images and low and high resolution long-slit spectra have been used to obtain maps of Ne, Te, c(Hbeta) and... more
We have studied the internal kinematics and physical conditions throughout the planetary nebula NGC 2371. Narrow-band images and low and high resolution long-slit spectra have been used to obtain maps of Ne, Te, c(Hbeta) and position-velocity diagrams. We found low electronic density, constant extinction and a complex kinematic structure in this planetary nebula.