M. Grosso - Academia.edu (original) (raw)
Papers by M. Grosso
The Astrophysical Journal, 2002
... Helmut A. Abt Kitt Peak National Observatory, PO Box 26732, Tucson, AZ 85726-6732; abt@noao.e... more ... Helmut A. Abt Kitt Peak National Observatory, PO Box 26732, Tucson, AZ 85726-6732; abt@noao.edu and Hugo Levato and Monica ... in Batten, Fletcher, & MacCarthy (1989), specific star identifications in doubles, and comments about the line character (n = broad, s = sharp). ...
![Research paper thumbnail of Toward Understanding the B[e] Phenomenon. II. New Galactic FS CMa Stars](https://attachments.academia-assets.com/41978202/thumbnails/1.jpg)
](The Astrophysical Journal, 2007
FS CMa stars form a group of objects with the B[e] phenomenon that were previously known as uncla... more FS CMa stars form a group of objects with the B[e] phenomenon that were previously known as unclassified B[e] stars or B[e] stars with warm dust (B[e]WD) until recently. They exhibit strong emission-line spectra and strong IR excesses, most likely due to recently formed circumstellar dust. These properties have been suggested to be due to ongoing or recent rapid mass exchange in binary systems with hot primaries and various types of secondaries. The first paper of this series reported an analysis of the available information about previously known Galactic objects with the B[e] phenomenon, the initial selection of the FS CMa group objects, and a qualitative explanation of their properties. This paper reports the results of our new search for more FS CMa objects in the IRAS Point Source Catalog. We present new photometric criteria for identifying FS CMa stars as well as the first results of our observations of nine new FS CMa group members. With this addition, the FS CMa group has now 40 members, becoming 1 Partially based on data obtained at the 6 m BTATelescope of the Russian Academy of Sciences, 3.6 m Canada-France-Hawaii Telescope, 3 m Shane Telescope of the Lick Observatory, 2.7 m Harlan J. Smith and 2.1 m Otto Struve Telescopes of the McDonald Observatory, 2.1 m telescope of the San Pedro Martir Observatory, 1.5 m telescope of the Loiano Observatory, and 0.8 m telescope of the Dark Sky Observatory.
Publications of the Astronomical Society of the Pacific, 2000
ABSTRACT We present the results of a determination of the preliminary orbital elements of the spe... more ABSTRACT We present the results of a determination of the preliminary orbital elements of the spectroscopic binary FMM 3 in the field of the open cluster Trumpler 14. The spectrum of this binary shows two sets of lines that are roughly similar. The period found was around 5 ...
Publications of the Astronomical Society of the Pacific, 1998
Title: Frequency of Binaries in the Open Cluster Trumpler 14. Authors: García, Beatriz; Malaroda,... more Title: Frequency of Binaries in the Open Cluster Trumpler 14. Authors: García, Beatriz; Malaroda, Stella; Levato, Hugo; Morrell, Nidia; Grosso, Mónica. Affiliation: AA(Complejo Astronómico El Leoncito, CC 467, 5400 San Juan ...
Monthly Notices of the Royal Astronomical Society, 2008
Extensive spectral observations of η Carinae over the last cycle, and particularly around the 200... more Extensive spectral observations of η Carinae over the last cycle, and particularly around the 2003.5 low-excitation event, have been obtained. The variability of both narrow and broad lines, when combined with data taken from two earlier cycles, reveal a common and welldefined period. We have combined the cycle lengths derived from the many lines in the optical spectrum with those from broad-band X-rays, optical and near-infrared observations, and obtained a period length of P pres = 2022.7 ± 1.3 d.
Monthly Notices of the Royal Astronomical Society, 2008
A full description of the 5.5-yr low excitation events in η Carinae is presented. We show that th... more A full description of the 5.5-yr low excitation events in η Carinae is presented. We show that they are not as simple and brief as previously thought, but a combination of two components. The first, the slow variation component, is revealed by slow changes in the ionization level of circumstellar matter across the whole cycle and is caused by gradual changes in the windwind collision shock-cone orientation, angular opening and gaseous content. The second, the collapse component, is restricted to around the minimum, and is due to a temporary global collapse of the wind-wind collision shock. High-energy photons (E > 16 eV) from the companion star are strongly shielded, leaving the Weigelt objects at low-ionization state for more than six months. High-energy phenomena are sensitive only to the collapse, low energy only to the slow variation and intermediate energies to both components. Simple eclipses and mechanisms effective only near periastron (e.g. shell ejection or accretion on to the secondary star) cannot account for the whole 5.5-yr cycle.
Journal of Nuclear Medicine, 2008
This review outlines the technical aspects and diagnostic performance parameters of nuclear medic... more This review outlines the technical aspects and diagnostic performance parameters of nuclear medicine procedures used on patients with disorders of the lower gastrointestinal tract, with the exclusion of techniques using tumor-seeking radiopharmaceuticals. Chronic disorders of the lower gastrointestinal tract often reduce the quality of life because of discomfort from constipation or diarrhea. Five classes of radionuclide procedures are used to characterize these disorders: transit scintigraphy, searches for ectopic gastric mucosa in Meckel's diverticulum, scintigraphy of active inflammatory bowel disease, scintigraphic defecography, and scintigraphy to detect sites of gastrointestinal bleeding. Protocols for these procedures and their relative merit in patient management are discussed, with special emphasis on their potential for semiquantitative assessment of the pathophysiologic parameter investigated. Quantitation is particularly relevant for prognostic purposes and for monitoring the efficacy of therapy.
We have observed all A type stars of the southern hemisphere brighter than 6.5 mag in order to pe... more We have observed all A type stars of the southern hemisphere brighter than 6.5 mag in order to perform statistical studies of axial rotation. The spectra were obtained at the 2.15 m telescope at CASLEO. We have used the method of Diaz et al. (2011) to calculate axial rotation velocities.
IEEE Transactions on Very Large Scale Integration (VLSI) Systems, 2000
... IEEE VLSI Test Symp., 2005, pp. 2934. [5] A. Paschalis and D ... IEEE Des. Autom. Test Eur.,... more ... IEEE VLSI Test Symp., 2005, pp. 2934. [5] A. Paschalis and D ... IEEE Des. Autom. Test Eur., 2007, pp. 16. [19] J. Lagos-Benites, Effective approach for the diagnosis of transition-delay faults in SOCs, based on SBST and scan chains, in Proc. IEEE DFT, 2007, pp. 291302. ...
IEEE Design & Test of Computers, 2000
AS MARKET DEMANDS have continued driving the design of faster, smaller, and cheaper devices, tech... more AS MARKET DEMANDS have continued driving the design of faster, smaller, and cheaper devices, technology has responded with component miniaturization that now allows the integration of many functional modules on a single silicon chip. The system-on-chip (SoC) paradigm guarantees better performance, smaller dimensions, and lower power consumption than the same circuit on PCBs. In addition, reuse of full-fledged modular components (cores) simplifies the design flow. SoC manufacturers can develop the cores in-house or buy them as IP and then assemble them in various complex systems. As for system implementation, however, high-volume production is necessary for a SoC manufacturer to amortize the high nonrecurring engineering costs.
Astrophysics and Space Science, 1991
In this paper we present radial velocity measurements &probable members of Trumpler 14, a very yo... more In this paper we present radial velocity measurements &probable members of Trumpler 14, a very young open cluster associated with the Carina Nebula. We have found 4 double-line spectroscopic binaries and 2 single-line spectroscopic binaries. We have succeeded in deriving orbital elements for the SBIs. All the binaries are of potential astrophysical interest and are worth further observational efforts.
The Astrophysical Journal Supplement Series, 1991
Astronomy and Astrophysics, 2001
We report the results of our spectroscopic observations (3600-5900 ûA, R ≃ 16000 and 5750-8750 ûA... more We report the results of our spectroscopic observations (3600-5900 ûA, R ≃ 16000 and 5750-8750 ûA, R ≃ 11000) of three southern emission-line B-type stars associated with IRAS sources, HD 85567, Hen3-140, and Hen3-1398, whose nature and evolutionary state are not well-established yet. We also obtained new multicolour photometry of HD 85567 (UBV (RI)cJHKL) and Hen3-140 (JHKLM). A large near-IR
Astronomy and Astrophysics, 2002
An analysis of the abundances of the Silicon star HD 206653 is presented using an ATLAS9 model at... more An analysis of the abundances of the Silicon star HD 206653 is presented using an ATLAS9 model atmosphere and observational material taken with a REOSC echelle spectrograph attached to the Jorge Sahade 2.15 m telescope at CASLEO. The light elements are solar or deficient except silicon which is overabundant by a factor of 5. The iron peak elements are all overabundant by factors between 10 and 50. Sr and Y are around 1000 times the solar values. Among the Rare Earths only Ce and Eu are identified; both are overabundant by large factors.
Astronomy and Astrophysics, 2003
We present the results of a spectroscopic monitoring program of the binary system δ Scorpii, whos... more We present the results of a spectroscopic monitoring program of the binary system δ Scorpii, whose primary became a Be star after the last periastron encounter in the Summer of 2000. The observations cover a period of 2 years (March 2001-June 2003 and are a continuation of our previous campaign reported in . We found that the emission-line spectrum was gradually strengthening over the whole monitoring period. Several short-term increases of the line emission, possibly due to outbursts of matter ejected from the stellar surface, were detected. The outbursts seem to be responsible for the brightness fadings, seen afterwards. We attempt to explain the overall observed line and continuum behaviour in terms of a circumstellar disk, growing in density and size. The disk is most likely Keplerian with an outer radius of ∼10 R and a mean expansion speed of ∼0.4 km s −1 .
![Research paper thumbnail of Properties of galactic B[e] supergiants](https://attachments.academia-assets.com/39578516/thumbnails/1.jpg)
](Astronomy and Astrophysics, 2004
We present the results of optical and near-IR spectroscopic and mid-IR imaging observations of th... more We present the results of optical and near-IR spectroscopic and mid-IR imaging observations of the emission-line star MWC 300. Its properties and evolutionary state are still under debate (a B[e] supergiant or a Herbig Be star). For the first time we detected radial velocity variations of the photospheric lines and found a correlation between them and those of the He λ5876 Å line. Most of the pure emission lines had stable positions for nearly 20 years. New estimates of the object's luminosity (log L/L = 5.1 ± 0.1), distance (D = 1.8 ± 0.2 kpc), and systemic velocity (+26 ± 2 km s −1 ) were derived. We found that both the circumstellar extinction in the disk-like dusty envelope and the interstellar extinction play a significant role in the attenuation of the stellar brightness. Our 2D modeling of the observed spectral energy distribution in the wavelength range from 0.3 µm to 1.3 mm suggests that the star is viewed through a gaseous-and-dusty flared disk with an opening angle of 30 • , an inclination angle of 10 • , an equatorial optical depth τ V = 3.0, and a total mass of 0.08 M . We argue that MWC 300 is most likely a binary system, because of the similarities of its observed parameters with those of recognized B[e] binaries.
Astronomy and Astrophysics Supplement Series, 1996
As part of a systematic project we have determined radial velocities and projected rotational vel... more As part of a systematic project we have determined radial velocities and projected rotational velocities for a sample of 186 chemically peculiar stars which have been observed by the Hipparcos' satellite. The purpose is to provide necessary data to study the space velocities of peculiar stars.
Astronomy & Astrophysics Supplement Series, 2000
We present a bibliographic catalogue of stellar radial velocities with 13359 entries for stars in... more We present a bibliographic catalogue of stellar radial velocities with 13359 entries for stars in the galaxy and the Magellanic Clouds, obtained from the issues of several journals published in the period 1991-1994. We have tried to follow the structure of previous compilations although we have relied on data retrived from the SIMBAD database. Catalogue available at the CDS via
The Astrophysical Journal, 2002
... Helmut A. Abt Kitt Peak National Observatory, PO Box 26732, Tucson, AZ 85726-6732; abt@noao.e... more ... Helmut A. Abt Kitt Peak National Observatory, PO Box 26732, Tucson, AZ 85726-6732; abt@noao.edu and Hugo Levato and Monica ... in Batten, Fletcher, & MacCarthy (1989), specific star identifications in doubles, and comments about the line character (n = broad, s = sharp). ...
The Astrophysical Journal, 2007
FS CMa stars form a group of objects with the B[e] phenomenon that were previously known as uncla... more FS CMa stars form a group of objects with the B[e] phenomenon that were previously known as unclassified B[e] stars or B[e] stars with warm dust (B[e]WD) until recently. They exhibit strong emission-line spectra and strong IR excesses, most likely due to recently formed circumstellar dust. These properties have been suggested to be due to ongoing or recent rapid mass exchange in binary systems with hot primaries and various types of secondaries. The first paper of this series reported an analysis of the available information about previously known Galactic objects with the B[e] phenomenon, the initial selection of the FS CMa group objects, and a qualitative explanation of their properties. This paper reports the results of our new search for more FS CMa objects in the IRAS Point Source Catalog. We present new photometric criteria for identifying FS CMa stars as well as the first results of our observations of nine new FS CMa group members. With this addition, the FS CMa group has now 40 members, becoming 1 Partially based on data obtained at the 6 m BTATelescope of the Russian Academy of Sciences, 3.6 m Canada-France-Hawaii Telescope, 3 m Shane Telescope of the Lick Observatory, 2.7 m Harlan J. Smith and 2.1 m Otto Struve Telescopes of the McDonald Observatory, 2.1 m telescope of the San Pedro Martir Observatory, 1.5 m telescope of the Loiano Observatory, and 0.8 m telescope of the Dark Sky Observatory.
Publications of the Astronomical Society of the Pacific, 2000
ABSTRACT We present the results of a determination of the preliminary orbital elements of the spe... more ABSTRACT We present the results of a determination of the preliminary orbital elements of the spectroscopic binary FMM 3 in the field of the open cluster Trumpler 14. The spectrum of this binary shows two sets of lines that are roughly similar. The period found was around 5 ...
Publications of the Astronomical Society of the Pacific, 1998
Title: Frequency of Binaries in the Open Cluster Trumpler 14. Authors: García, Beatriz; Malaroda,... more Title: Frequency of Binaries in the Open Cluster Trumpler 14. Authors: García, Beatriz; Malaroda, Stella; Levato, Hugo; Morrell, Nidia; Grosso, Mónica. Affiliation: AA(Complejo Astronómico El Leoncito, CC 467, 5400 San Juan ...
Monthly Notices of the Royal Astronomical Society, 2008
Extensive spectral observations of η Carinae over the last cycle, and particularly around the 200... more Extensive spectral observations of η Carinae over the last cycle, and particularly around the 2003.5 low-excitation event, have been obtained. The variability of both narrow and broad lines, when combined with data taken from two earlier cycles, reveal a common and welldefined period. We have combined the cycle lengths derived from the many lines in the optical spectrum with those from broad-band X-rays, optical and near-infrared observations, and obtained a period length of P pres = 2022.7 ± 1.3 d.
Monthly Notices of the Royal Astronomical Society, 2008
A full description of the 5.5-yr low excitation events in η Carinae is presented. We show that th... more A full description of the 5.5-yr low excitation events in η Carinae is presented. We show that they are not as simple and brief as previously thought, but a combination of two components. The first, the slow variation component, is revealed by slow changes in the ionization level of circumstellar matter across the whole cycle and is caused by gradual changes in the windwind collision shock-cone orientation, angular opening and gaseous content. The second, the collapse component, is restricted to around the minimum, and is due to a temporary global collapse of the wind-wind collision shock. High-energy photons (E > 16 eV) from the companion star are strongly shielded, leaving the Weigelt objects at low-ionization state for more than six months. High-energy phenomena are sensitive only to the collapse, low energy only to the slow variation and intermediate energies to both components. Simple eclipses and mechanisms effective only near periastron (e.g. shell ejection or accretion on to the secondary star) cannot account for the whole 5.5-yr cycle.
Journal of Nuclear Medicine, 2008
This review outlines the technical aspects and diagnostic performance parameters of nuclear medic... more This review outlines the technical aspects and diagnostic performance parameters of nuclear medicine procedures used on patients with disorders of the lower gastrointestinal tract, with the exclusion of techniques using tumor-seeking radiopharmaceuticals. Chronic disorders of the lower gastrointestinal tract often reduce the quality of life because of discomfort from constipation or diarrhea. Five classes of radionuclide procedures are used to characterize these disorders: transit scintigraphy, searches for ectopic gastric mucosa in Meckel's diverticulum, scintigraphy of active inflammatory bowel disease, scintigraphic defecography, and scintigraphy to detect sites of gastrointestinal bleeding. Protocols for these procedures and their relative merit in patient management are discussed, with special emphasis on their potential for semiquantitative assessment of the pathophysiologic parameter investigated. Quantitation is particularly relevant for prognostic purposes and for monitoring the efficacy of therapy.
We have observed all A type stars of the southern hemisphere brighter than 6.5 mag in order to pe... more We have observed all A type stars of the southern hemisphere brighter than 6.5 mag in order to perform statistical studies of axial rotation. The spectra were obtained at the 2.15 m telescope at CASLEO. We have used the method of Diaz et al. (2011) to calculate axial rotation velocities.
IEEE Transactions on Very Large Scale Integration (VLSI) Systems, 2000
... IEEE VLSI Test Symp., 2005, pp. 2934. [5] A. Paschalis and D ... IEEE Des. Autom. Test Eur.,... more ... IEEE VLSI Test Symp., 2005, pp. 2934. [5] A. Paschalis and D ... IEEE Des. Autom. Test Eur., 2007, pp. 16. [19] J. Lagos-Benites, Effective approach for the diagnosis of transition-delay faults in SOCs, based on SBST and scan chains, in Proc. IEEE DFT, 2007, pp. 291302. ...
IEEE Design & Test of Computers, 2000
AS MARKET DEMANDS have continued driving the design of faster, smaller, and cheaper devices, tech... more AS MARKET DEMANDS have continued driving the design of faster, smaller, and cheaper devices, technology has responded with component miniaturization that now allows the integration of many functional modules on a single silicon chip. The system-on-chip (SoC) paradigm guarantees better performance, smaller dimensions, and lower power consumption than the same circuit on PCBs. In addition, reuse of full-fledged modular components (cores) simplifies the design flow. SoC manufacturers can develop the cores in-house or buy them as IP and then assemble them in various complex systems. As for system implementation, however, high-volume production is necessary for a SoC manufacturer to amortize the high nonrecurring engineering costs.
Astrophysics and Space Science, 1991
In this paper we present radial velocity measurements &probable members of Trumpler 14, a very yo... more In this paper we present radial velocity measurements &probable members of Trumpler 14, a very young open cluster associated with the Carina Nebula. We have found 4 double-line spectroscopic binaries and 2 single-line spectroscopic binaries. We have succeeded in deriving orbital elements for the SBIs. All the binaries are of potential astrophysical interest and are worth further observational efforts.
The Astrophysical Journal Supplement Series, 1991
Astronomy and Astrophysics, 2001
We report the results of our spectroscopic observations (3600-5900 ûA, R ≃ 16000 and 5750-8750 ûA... more We report the results of our spectroscopic observations (3600-5900 ûA, R ≃ 16000 and 5750-8750 ûA, R ≃ 11000) of three southern emission-line B-type stars associated with IRAS sources, HD 85567, Hen3-140, and Hen3-1398, whose nature and evolutionary state are not well-established yet. We also obtained new multicolour photometry of HD 85567 (UBV (RI)cJHKL) and Hen3-140 (JHKLM). A large near-IR
Astronomy and Astrophysics, 2002
An analysis of the abundances of the Silicon star HD 206653 is presented using an ATLAS9 model at... more An analysis of the abundances of the Silicon star HD 206653 is presented using an ATLAS9 model atmosphere and observational material taken with a REOSC echelle spectrograph attached to the Jorge Sahade 2.15 m telescope at CASLEO. The light elements are solar or deficient except silicon which is overabundant by a factor of 5. The iron peak elements are all overabundant by factors between 10 and 50. Sr and Y are around 1000 times the solar values. Among the Rare Earths only Ce and Eu are identified; both are overabundant by large factors.
Astronomy and Astrophysics, 2003
We present the results of a spectroscopic monitoring program of the binary system δ Scorpii, whos... more We present the results of a spectroscopic monitoring program of the binary system δ Scorpii, whose primary became a Be star after the last periastron encounter in the Summer of 2000. The observations cover a period of 2 years (March 2001-June 2003 and are a continuation of our previous campaign reported in . We found that the emission-line spectrum was gradually strengthening over the whole monitoring period. Several short-term increases of the line emission, possibly due to outbursts of matter ejected from the stellar surface, were detected. The outbursts seem to be responsible for the brightness fadings, seen afterwards. We attempt to explain the overall observed line and continuum behaviour in terms of a circumstellar disk, growing in density and size. The disk is most likely Keplerian with an outer radius of ∼10 R and a mean expansion speed of ∼0.4 km s −1 .
Astronomy and Astrophysics, 2004
We present the results of optical and near-IR spectroscopic and mid-IR imaging observations of th... more We present the results of optical and near-IR spectroscopic and mid-IR imaging observations of the emission-line star MWC 300. Its properties and evolutionary state are still under debate (a B[e] supergiant or a Herbig Be star). For the first time we detected radial velocity variations of the photospheric lines and found a correlation between them and those of the He λ5876 Å line. Most of the pure emission lines had stable positions for nearly 20 years. New estimates of the object's luminosity (log L/L = 5.1 ± 0.1), distance (D = 1.8 ± 0.2 kpc), and systemic velocity (+26 ± 2 km s −1 ) were derived. We found that both the circumstellar extinction in the disk-like dusty envelope and the interstellar extinction play a significant role in the attenuation of the stellar brightness. Our 2D modeling of the observed spectral energy distribution in the wavelength range from 0.3 µm to 1.3 mm suggests that the star is viewed through a gaseous-and-dusty flared disk with an opening angle of 30 • , an inclination angle of 10 • , an equatorial optical depth τ V = 3.0, and a total mass of 0.08 M . We argue that MWC 300 is most likely a binary system, because of the similarities of its observed parameters with those of recognized B[e] binaries.
Astronomy and Astrophysics Supplement Series, 1996
As part of a systematic project we have determined radial velocities and projected rotational vel... more As part of a systematic project we have determined radial velocities and projected rotational velocities for a sample of 186 chemically peculiar stars which have been observed by the Hipparcos' satellite. The purpose is to provide necessary data to study the space velocities of peculiar stars.
Astronomy & Astrophysics Supplement Series, 2000
We present a bibliographic catalogue of stellar radial velocities with 13359 entries for stars in... more We present a bibliographic catalogue of stellar radial velocities with 13359 entries for stars in the galaxy and the Magellanic Clouds, obtained from the issues of several journals published in the period 1991-1994. We have tried to follow the structure of previous compilations although we have relied on data retrived from the SIMBAD database. Catalogue available at the CDS via