Katia Genovali | Consiglio Nazionale delle Ricerche (CNR) (original) (raw)
Papers by Katia Genovali
Classical Cepheids are useful tracers of the Galactic young stellar population because their dist... more Classical Cepheids are useful tracers of the Galactic young stellar population because their distances and ages can be determined from their period-luminosity and period-age relations. In addition, the radial velocities and chemical abundance of the Cepheids can be derived from spectroscopic observations, providing further insights into the structure and evolution of the Galaxy. Here, we report the radial velocities of classical Cepheids near the Galactic Center, three of which were reported in 2011, the other reported for the first time. The velocities of these Cepheids suggest that the stars orbit within the Nuclear Stellar Disk, a group of stars and interstellar matter occupying a region of ∼ 200 pc around the Center, although the three-dimensional velocities cannot be determined until the proper motions are known. According to our simulation, these four Cepheids formed within the Nuclear Stellar Disk like younger stars and stellar clusters therein.
Scopo di questa tesi è mostrare l'evoluzione del sistema simbiotico AG Dra dal punto di vista... more Scopo di questa tesi è mostrare l'evoluzione del sistema simbiotico AG Dra dal punto di vista delle variazioni spettroscopiche che hanno caratterizzato gli ultimi anni di attività. Misure di larghezza equivalente sono state effettate per tutte le righe di emissione degli spettri originali a nostra disposizione. I risultati sono stati inquadrati nell'ambito di quelli già noti dalla letteratura. Sono presentati inoltre i cataloghi di profili spettrali ad alta risoluzione della stella
The Astrophysical Journal, 2015
Classical Cepheids are useful tracers of the Galactic young stellar population because their dist... more Classical Cepheids are useful tracers of the Galactic young stellar population because their distances and ages can be determined from their period-luminosity and period-age relations. In addition, the radial velocities and chemical abundance of the Cepheids can be derived from spectroscopic observations, providing further insights into the structure and evolution of the Galaxy. Here, we report the radial velocities of classical Cepheids near the Galactic Center, three of which were reported in 2011, the other reported for the first time. The velocities of these Cepheids suggest that the stars orbit within the Nuclear Stellar Disk, a group of stars and interstellar matter occupying a region of ∼ 200 pc around the Center, although the three-dimensional velocities cannot be determined until the proper motions are known. According to our simulation, these four Cepheids formed within the Nuclear Stellar Disk like younger stars and stellar clusters therein.
Proceedings of the International Astronomical Union, 2013
We are carrying out near-infrared spectroscopy of Cepheids in the Galactic nuclear disk. The H-ba... more We are carrying out near-infrared spectroscopy of Cepheids in the Galactic nuclear disk. The H-band spectra taken with SUBARU/IRCS indicate that their kinematics are consistent with the rotation of the nuclear disk.
Astronomy and Astrophysics, 2010
The spectroscopic evolution of the symbiotic star AG Draconis I. The O VI Raman, Balmer, and heli... more The spectroscopic evolution of the symbiotic star AG Draconis I. The O VI Raman, Balmer, and helium emission line variations during the outburst of 2006−2008
Open Astronomy, 2012
We present some results of an ongoing study of the long-term spectroscopic variations of AG Dra, ... more We present some results of an ongoing study of the long-term spectroscopic variations of AG Dra, a prototypical eruptive symbiotic system. We discuss the effects of the environment and orbital modulation in this system and some of the physical processes revealed by a comparison with the nova outburst of the symbiotic-like recurrent nova V407 Cyg 2010.
arXiv: Solar and Stellar Astrophysics, 2011
We present some recent findings concerning the use of RR Lyrae as distance indicators and stellar... more We present some recent findings concerning the use of RR Lyrae as distance indicators and stellar tracers. We outline pros and cons of field and cluster RR Lyrae stars and discuss recent theoretical findings concerning the use of the Bailey (amplitude vs pulsation period) diagram to constrain the possible occurrence of Helium enhanced RR Lyrae stars. Nonlinear, convective RR Lyrae models indicate that the pulsation properties of RR Lyrae stars are minimally affected by the helium content. The main difference between canonical and He enhanced models is due to the increase in luminosity predicted by evolutionary models. Moreover, we focus our attention on the near-infrared Period-Luminosity (PL) relation of RR Lyrae and summarize observational evidence concerning the slope of the K-band PL relation in a few globulars (M92, Reticulum, M5, Omega Cen) covering a range in metallicity of ~1 dex. Current findings suggest that the slope has a mild dependence on the metal content when moving ...
Classical Cepheids are useful tracers of the Galactic young stellar population because their dist... more Classical Cepheids are useful tracers of the Galactic young stellar population because their distances and ages can be determined from their period-luminosity and period-age relations. In addition, the radial velocities and chemical abundance of the Cepheids can be derived from spectroscopic observations, providing further insights into the structure and evolution of the Galaxy. Here, we report the radial velocities of classical Cepheids near the Galactic Center, three of which were reported in 2011, the other reported for the first time. The velocities of these Cepheids suggest that the stars orbit within the Nuclear Stellar Disk, a group of stars and interstellar matter occupying a region of ∼ 200 pc around the Center, although the three-dimensional velocities cannot be determined until the proper motions are known. According to our simulation, these four Cepheids formed within the Nuclear Stellar Disk like younger stars and stellar clusters therein.
Scopo di questa tesi è mostrare l'evoluzione del sistema simbiotico AG Dra dal punto di vista... more Scopo di questa tesi è mostrare l'evoluzione del sistema simbiotico AG Dra dal punto di vista delle variazioni spettroscopiche che hanno caratterizzato gli ultimi anni di attività. Misure di larghezza equivalente sono state effettate per tutte le righe di emissione degli spettri originali a nostra disposizione. I risultati sono stati inquadrati nell'ambito di quelli già noti dalla letteratura. Sono presentati inoltre i cataloghi di profili spettrali ad alta risoluzione della stella
The Astrophysical Journal, 2015
Classical Cepheids are useful tracers of the Galactic young stellar population because their dist... more Classical Cepheids are useful tracers of the Galactic young stellar population because their distances and ages can be determined from their period-luminosity and period-age relations. In addition, the radial velocities and chemical abundance of the Cepheids can be derived from spectroscopic observations, providing further insights into the structure and evolution of the Galaxy. Here, we report the radial velocities of classical Cepheids near the Galactic Center, three of which were reported in 2011, the other reported for the first time. The velocities of these Cepheids suggest that the stars orbit within the Nuclear Stellar Disk, a group of stars and interstellar matter occupying a region of ∼ 200 pc around the Center, although the three-dimensional velocities cannot be determined until the proper motions are known. According to our simulation, these four Cepheids formed within the Nuclear Stellar Disk like younger stars and stellar clusters therein.
Proceedings of the International Astronomical Union, 2013
We are carrying out near-infrared spectroscopy of Cepheids in the Galactic nuclear disk. The H-ba... more We are carrying out near-infrared spectroscopy of Cepheids in the Galactic nuclear disk. The H-band spectra taken with SUBARU/IRCS indicate that their kinematics are consistent with the rotation of the nuclear disk.
Astronomy and Astrophysics, 2010
The spectroscopic evolution of the symbiotic star AG Draconis I. The O VI Raman, Balmer, and heli... more The spectroscopic evolution of the symbiotic star AG Draconis I. The O VI Raman, Balmer, and helium emission line variations during the outburst of 2006−2008
Open Astronomy, 2012
We present some results of an ongoing study of the long-term spectroscopic variations of AG Dra, ... more We present some results of an ongoing study of the long-term spectroscopic variations of AG Dra, a prototypical eruptive symbiotic system. We discuss the effects of the environment and orbital modulation in this system and some of the physical processes revealed by a comparison with the nova outburst of the symbiotic-like recurrent nova V407 Cyg 2010.
arXiv: Solar and Stellar Astrophysics, 2011
We present some recent findings concerning the use of RR Lyrae as distance indicators and stellar... more We present some recent findings concerning the use of RR Lyrae as distance indicators and stellar tracers. We outline pros and cons of field and cluster RR Lyrae stars and discuss recent theoretical findings concerning the use of the Bailey (amplitude vs pulsation period) diagram to constrain the possible occurrence of Helium enhanced RR Lyrae stars. Nonlinear, convective RR Lyrae models indicate that the pulsation properties of RR Lyrae stars are minimally affected by the helium content. The main difference between canonical and He enhanced models is due to the increase in luminosity predicted by evolutionary models. Moreover, we focus our attention on the near-infrared Period-Luminosity (PL) relation of RR Lyrae and summarize observational evidence concerning the slope of the K-band PL relation in a few globulars (M92, Reticulum, M5, Omega Cen) covering a range in metallicity of ~1 dex. Current findings suggest that the slope has a mild dependence on the metal content when moving ...