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Dipankar Banerjee - One of the best experts on this subject based on the ideXlab platform.
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association of Plages with sunspots a multi wavelength study using kodaikanal ca ii k and greenwich sunspot area data
The Astrophysical Journal, 2017Co-Authors: Sudip Mandal, Subhamoy Chatterjee, Dipankar BanerjeeAbstract:Plages are the magnetically active chromospheric structures prominently visible in the Ca ii K line (3933.67 A). A plage may or may not be associated with a sunspot, which is a magnetic structure visible in the solar photosphere. In this study we explore this aspect of association of Plages with sunspots using the newly digitized Kodaikanal Ca ii K plage data and the Greenwich sunspot area data. Instead of using the plage index or fractional plage area and its comparison with the sunspot number, we use, to our knowledge for the first time, the individual plage areas and compare them with the sunspot area time series. Our analysis shows that these two structures, formed in two different layers, are highly correlated with each other on a timescale comparable to the solar cycle. The area and the latitudinal distributions of Plages are also similar to those of sunspots. Different area thresholdings on the "butterfly diagram" reveal that Plages of area ≥4 arcmin2 are mostly associated with a sunspot in the photosphere. Apart from this, we found that the cyclic properties change when Plages of different sizes are considered separately. These results may help us to better understand the generation and evolution of the magnetic structures in different layers of the solar atmosphere.
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Association of Plages With Sunspots: A multi wavelength Study Using Kodaikanal Ca $\scriptsize{{\textrm{II}}}$ K and Greenwich sunspot area Data
The Astrophysical Journal, 2017Co-Authors: Sudip Mandal, Subhamoy Chatterjee, Dipankar BanerjeeAbstract:Plages are the magnetically active chromospheric structures prominently visible in Ca $\scriptsize{\textrm{II}}$ K line (3933.67 A). A plage may or may not be associated with a sunspot which is a magnetic structure visible in the solar photosphere. In this study we explore this aspect of association of Plages with sunspots using the newly digitized Kodaikanal Ca $\scriptsize{\textrm{II}}$ K plage data and the Greenwich sunspot area data. Instead of using the plage index or fractional plage area and their comparison with the sunspot number, we use, to our knowledge for the first time, the individual plage areas and compared it with the sunspot area time series. Our analysis shows that these two structures formed at two different layers are highly correlated with each other on a time scale comparable to the solar cycle. The area and the latitudinal distributions of Plages are also similar to that of the sunspots. Different area thresholdings on the `Butterfly diagram' reveal that Plages with area $\geq$4 arcmin$^2$ are mostly associated with a sunspot in the photosphere. Apart from this, we found that the cyclic properties change when different sized Plages are considered separately. These results may help us to better understand the generation and the evolution of the magnetic structures in different layers of the solar atmosphere.
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association of Plages with sunspots a multi wavelength study using kodaikanal ca scriptsize textrm ii k and greenwich sunspot area data
arXiv: Solar and Stellar Astrophysics, 2016Co-Authors: Sudip Mandal, Subhamoy Chatterjee, Dipankar BanerjeeAbstract:Plages are the magnetically active chromospheric structures prominently visible in Ca $\scriptsize{\textrm{II}}$ K line (3933.67 A). A plage may or may not be associated with a sunspot which is a magnetic structure visible in the solar photosphere. In this study we explore this aspect of association of Plages with sunspots using the newly digitized Kodaikanal Ca $\scriptsize{\textrm{II}}$ K plage data and the Greenwich sunspot area data. Instead of using the plage index or fractional plage area and their comparison with the sunspot number, we use, to our knowledge for the first time, the individual plage areas and compared it with the sunspot area time series. Our analysis shows that these two structures formed at two different layers are highly correlated with each other on a time scale comparable to the solar cycle. The area and the latitudinal distributions of Plages are also similar to that of the sunspots. Different area thresholdings on the `Butterfly diagram' reveal that Plages with area $\geq$4 arcmin$^2$ are mostly associated with a sunspot in the photosphere. Apart from this, we found that the cyclic properties change when different sized Plages are considered separately. These results may help us to better understand the generation and the evolution of the magnetic structures in different layers of the solar atmosphere.
Sudip Mandal - One of the best experts on this subject based on the ideXlab platform.
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association of Plages with sunspots a multi wavelength study using kodaikanal ca ii k and greenwich sunspot area data
The Astrophysical Journal, 2017Co-Authors: Sudip Mandal, Subhamoy Chatterjee, Dipankar BanerjeeAbstract:Plages are the magnetically active chromospheric structures prominently visible in the Ca ii K line (3933.67 A). A plage may or may not be associated with a sunspot, which is a magnetic structure visible in the solar photosphere. In this study we explore this aspect of association of Plages with sunspots using the newly digitized Kodaikanal Ca ii K plage data and the Greenwich sunspot area data. Instead of using the plage index or fractional plage area and its comparison with the sunspot number, we use, to our knowledge for the first time, the individual plage areas and compare them with the sunspot area time series. Our analysis shows that these two structures, formed in two different layers, are highly correlated with each other on a timescale comparable to the solar cycle. The area and the latitudinal distributions of Plages are also similar to those of sunspots. Different area thresholdings on the "butterfly diagram" reveal that Plages of area ≥4 arcmin2 are mostly associated with a sunspot in the photosphere. Apart from this, we found that the cyclic properties change when Plages of different sizes are considered separately. These results may help us to better understand the generation and evolution of the magnetic structures in different layers of the solar atmosphere.
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Association of Plages With Sunspots: A multi wavelength Study Using Kodaikanal Ca $\scriptsize{{\textrm{II}}}$ K and Greenwich sunspot area Data
The Astrophysical Journal, 2017Co-Authors: Sudip Mandal, Subhamoy Chatterjee, Dipankar BanerjeeAbstract:Plages are the magnetically active chromospheric structures prominently visible in Ca $\scriptsize{\textrm{II}}$ K line (3933.67 A). A plage may or may not be associated with a sunspot which is a magnetic structure visible in the solar photosphere. In this study we explore this aspect of association of Plages with sunspots using the newly digitized Kodaikanal Ca $\scriptsize{\textrm{II}}$ K plage data and the Greenwich sunspot area data. Instead of using the plage index or fractional plage area and their comparison with the sunspot number, we use, to our knowledge for the first time, the individual plage areas and compared it with the sunspot area time series. Our analysis shows that these two structures formed at two different layers are highly correlated with each other on a time scale comparable to the solar cycle. The area and the latitudinal distributions of Plages are also similar to that of the sunspots. Different area thresholdings on the `Butterfly diagram' reveal that Plages with area $\geq$4 arcmin$^2$ are mostly associated with a sunspot in the photosphere. Apart from this, we found that the cyclic properties change when different sized Plages are considered separately. These results may help us to better understand the generation and the evolution of the magnetic structures in different layers of the solar atmosphere.
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association of Plages with sunspots a multi wavelength study using kodaikanal ca scriptsize textrm ii k and greenwich sunspot area data
arXiv: Solar and Stellar Astrophysics, 2016Co-Authors: Sudip Mandal, Subhamoy Chatterjee, Dipankar BanerjeeAbstract:Plages are the magnetically active chromospheric structures prominently visible in Ca $\scriptsize{\textrm{II}}$ K line (3933.67 A). A plage may or may not be associated with a sunspot which is a magnetic structure visible in the solar photosphere. In this study we explore this aspect of association of Plages with sunspots using the newly digitized Kodaikanal Ca $\scriptsize{\textrm{II}}$ K plage data and the Greenwich sunspot area data. Instead of using the plage index or fractional plage area and their comparison with the sunspot number, we use, to our knowledge for the first time, the individual plage areas and compared it with the sunspot area time series. Our analysis shows that these two structures formed at two different layers are highly correlated with each other on a time scale comparable to the solar cycle. The area and the latitudinal distributions of Plages are also similar to that of the sunspots. Different area thresholdings on the `Butterfly diagram' reveal that Plages with area $\geq$4 arcmin$^2$ are mostly associated with a sunspot in the photosphere. Apart from this, we found that the cyclic properties change when different sized Plages are considered separately. These results may help us to better understand the generation and the evolution of the magnetic structures in different layers of the solar atmosphere.
X. Dumusque - One of the best experts on this subject based on the ideXlab platform.
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SOAP 2.0: A TOOL TO ESTIMATE THE PHOTOMETRIC AND RADIAL VELOCITY VARIATIONS INDUCED BY S℡LAR SPOTS AND Plages
The Astrophysical Journal, 2014Co-Authors: X. Dumusque, I. Boisse, N. C. SantosAbstract:This paper presents SOAP 2.0, a new version of the Spot Oscillation And Planet (SOAP) code that estimates in a simple way the photometric and radial velocity (RV) variations induced by active regions. The inhibition of the convective blueshift (CB) inside active regions is considered, as well as the limb brightening effect of Plages, a quadratic limb darkening law, and a realistic spot and plage contrast ratio. SOAP 2.0 shows that the activity-induced variation of Plages is dominated by the inhibition of the CB effect. For spots, this effect becomes significant only for slow rotators. In addition, in the case of a major active region dominating the activity-induced signal, the ratio between the FWHM and the RV peak-to-peak amplitudes of the cross correlation function can be used to infer the type of active region responsible for the signal for stars with v sin i \textless= 8 kms(-1). A ratio smaller than three implies a spot, while a larger ratio implies a plage. Using the observation of HD 189733, we show that SOAP 2.0 manages to reproduce the activity variation as well as previous simulations when a spot is dominating the activity-induced variation. In addition, SOAP 2.0 also reproduces the activity variation induced by a plage on the slowly rotating star alpha Cen B, which is not possible using previous simulations. Following these results, SOAP 2.0 can be used to estimate the signal induced by spots and Plages, but also to correct for it when a major active region is dominating the RV variation.
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soap 2 0 a tool to estimate the photometric and radial velocity variations induced by stellar spots and Plages
The Astrophysical Journal, 2014Co-Authors: X. Dumusque, I Oisse, N. C. SantosAbstract:This paper presents SOAP 2.0, a new version of the Spot Oscillation And Planet (SOAP) code that estimates in a simple way the photometric and radial velocity (RV) variations induced by active regions. The inhibition of the convective blueshift (CB) inside active regions is considered, as well as the limb brightening effect of Plages, a quadratic limb darkening law, and a realistic spot and plage contrast ratio. SOAP 2.0 shows that the activity-induced variation of Plages is dominated by the inhibition of the CB effect. For spots, this effect becomes significant only for slow rotators. In addition, in the case of a major active region dominating the activity-induced signal, the ratio between the FWHM and the RV peak-to-peak amplitudes of the cross correlation function can be used to infer the type of active region responsible for the signal for stars with v sin i ≤8 km s{sup –1}. A ratio smaller than three implies a spot, while a larger ratio implies a plage. Using the observation of HD 189733, we show that SOAP 2.0 manages to reproduce the activity variation as well as previous simulations when a spot is dominating the activity-induced variation. In addition, SOAP 2.0 also reproduces themore » activity variation induced by a plage on the slowly rotating star α Cen B, which is not possible using previous simulations. Following these results, SOAP 2.0 can be used to estimate the signal induced by spots and Plages, but also to correct for it when a major active region is dominating the RV variation.« less
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soap 2 0 a tool to estimate the photometric and radial velocity variations induced by stellar spots and Plages
arXiv: Solar and Stellar Astrophysics, 2014Co-Authors: X. Dumusque, I. Boisse, N. C. SantosAbstract:This paper presents SOAP 2.0, a new version of the SOAP code that estimates in a simple way the photometric and radial velocity variations induced by active regions. The inhibition of the convective blueshift inside active regions is considered, as well as the limb brightening effect of Plages, a quadratic limb darkening law, and a realistic spot and plage contrast ratio. SOAP 2.0 shows that the activity-induced variation of Plages is dominated by the inhibition of the convective blueshift effect. For spots, this effect becomes significant only for slow rotators. In addition, in the case of a major active region dominating the activity-induced signal, the ratio between the full width at half maximum (FWHM) and the RV peak-to-peak amplitudes of the cross correlation function can be used to infer the type of active region responsible for the signal for stars with \vsini$\le8$\kms. A ratio smaller than three implies a spot, while a larger ratio implies a plage. Using the observation of HD189733, we show that SOAP 2.0 manages to reproduce the activity variation as well as previous simulations when a spot is dominating the activity-induced variation. In addition, SOAP 2.0 also reproduces the activity variation induced by a plage on the slowly rotating star $\alpha$ Cen B, which is not possible using previous simulations. Following these results, SOAP 2.0 can be used to estimate the signal induced by spots and Plages, but also to correct for it when a major active region is dominating the RV variation.
N. C. Santos - One of the best experts on this subject based on the ideXlab platform.
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SOAP 2.0: A TOOL TO ESTIMATE THE PHOTOMETRIC AND RADIAL VELOCITY VARIATIONS INDUCED BY S℡LAR SPOTS AND Plages
The Astrophysical Journal, 2014Co-Authors: X. Dumusque, I. Boisse, N. C. SantosAbstract:This paper presents SOAP 2.0, a new version of the Spot Oscillation And Planet (SOAP) code that estimates in a simple way the photometric and radial velocity (RV) variations induced by active regions. The inhibition of the convective blueshift (CB) inside active regions is considered, as well as the limb brightening effect of Plages, a quadratic limb darkening law, and a realistic spot and plage contrast ratio. SOAP 2.0 shows that the activity-induced variation of Plages is dominated by the inhibition of the CB effect. For spots, this effect becomes significant only for slow rotators. In addition, in the case of a major active region dominating the activity-induced signal, the ratio between the FWHM and the RV peak-to-peak amplitudes of the cross correlation function can be used to infer the type of active region responsible for the signal for stars with v sin i \textless= 8 kms(-1). A ratio smaller than three implies a spot, while a larger ratio implies a plage. Using the observation of HD 189733, we show that SOAP 2.0 manages to reproduce the activity variation as well as previous simulations when a spot is dominating the activity-induced variation. In addition, SOAP 2.0 also reproduces the activity variation induced by a plage on the slowly rotating star alpha Cen B, which is not possible using previous simulations. Following these results, SOAP 2.0 can be used to estimate the signal induced by spots and Plages, but also to correct for it when a major active region is dominating the RV variation.
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soap 2 0 a tool to estimate the photometric and radial velocity variations induced by stellar spots and Plages
The Astrophysical Journal, 2014Co-Authors: X. Dumusque, I Oisse, N. C. SantosAbstract:This paper presents SOAP 2.0, a new version of the Spot Oscillation And Planet (SOAP) code that estimates in a simple way the photometric and radial velocity (RV) variations induced by active regions. The inhibition of the convective blueshift (CB) inside active regions is considered, as well as the limb brightening effect of Plages, a quadratic limb darkening law, and a realistic spot and plage contrast ratio. SOAP 2.0 shows that the activity-induced variation of Plages is dominated by the inhibition of the CB effect. For spots, this effect becomes significant only for slow rotators. In addition, in the case of a major active region dominating the activity-induced signal, the ratio between the FWHM and the RV peak-to-peak amplitudes of the cross correlation function can be used to infer the type of active region responsible for the signal for stars with v sin i ≤8 km s{sup –1}. A ratio smaller than three implies a spot, while a larger ratio implies a plage. Using the observation of HD 189733, we show that SOAP 2.0 manages to reproduce the activity variation as well as previous simulations when a spot is dominating the activity-induced variation. In addition, SOAP 2.0 also reproduces themore » activity variation induced by a plage on the slowly rotating star α Cen B, which is not possible using previous simulations. Following these results, SOAP 2.0 can be used to estimate the signal induced by spots and Plages, but also to correct for it when a major active region is dominating the RV variation.« less
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soap 2 0 a tool to estimate the photometric and radial velocity variations induced by stellar spots and Plages
arXiv: Solar and Stellar Astrophysics, 2014Co-Authors: X. Dumusque, I. Boisse, N. C. SantosAbstract:This paper presents SOAP 2.0, a new version of the SOAP code that estimates in a simple way the photometric and radial velocity variations induced by active regions. The inhibition of the convective blueshift inside active regions is considered, as well as the limb brightening effect of Plages, a quadratic limb darkening law, and a realistic spot and plage contrast ratio. SOAP 2.0 shows that the activity-induced variation of Plages is dominated by the inhibition of the convective blueshift effect. For spots, this effect becomes significant only for slow rotators. In addition, in the case of a major active region dominating the activity-induced signal, the ratio between the full width at half maximum (FWHM) and the RV peak-to-peak amplitudes of the cross correlation function can be used to infer the type of active region responsible for the signal for stars with \vsini$\le8$\kms. A ratio smaller than three implies a spot, while a larger ratio implies a plage. Using the observation of HD189733, we show that SOAP 2.0 manages to reproduce the activity variation as well as previous simulations when a spot is dominating the activity-induced variation. In addition, SOAP 2.0 also reproduces the activity variation induced by a plage on the slowly rotating star $\alpha$ Cen B, which is not possible using previous simulations. Following these results, SOAP 2.0 can be used to estimate the signal induced by spots and Plages, but also to correct for it when a major active region is dominating the RV variation.
Subhamoy Chatterjee - One of the best experts on this subject based on the ideXlab platform.
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association of Plages with sunspots a multi wavelength study using kodaikanal ca ii k and greenwich sunspot area data
The Astrophysical Journal, 2017Co-Authors: Sudip Mandal, Subhamoy Chatterjee, Dipankar BanerjeeAbstract:Plages are the magnetically active chromospheric structures prominently visible in the Ca ii K line (3933.67 A). A plage may or may not be associated with a sunspot, which is a magnetic structure visible in the solar photosphere. In this study we explore this aspect of association of Plages with sunspots using the newly digitized Kodaikanal Ca ii K plage data and the Greenwich sunspot area data. Instead of using the plage index or fractional plage area and its comparison with the sunspot number, we use, to our knowledge for the first time, the individual plage areas and compare them with the sunspot area time series. Our analysis shows that these two structures, formed in two different layers, are highly correlated with each other on a timescale comparable to the solar cycle. The area and the latitudinal distributions of Plages are also similar to those of sunspots. Different area thresholdings on the "butterfly diagram" reveal that Plages of area ≥4 arcmin2 are mostly associated with a sunspot in the photosphere. Apart from this, we found that the cyclic properties change when Plages of different sizes are considered separately. These results may help us to better understand the generation and evolution of the magnetic structures in different layers of the solar atmosphere.
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Association of Plages With Sunspots: A multi wavelength Study Using Kodaikanal Ca $\scriptsize{{\textrm{II}}}$ K and Greenwich sunspot area Data
The Astrophysical Journal, 2017Co-Authors: Sudip Mandal, Subhamoy Chatterjee, Dipankar BanerjeeAbstract:Plages are the magnetically active chromospheric structures prominently visible in Ca $\scriptsize{\textrm{II}}$ K line (3933.67 A). A plage may or may not be associated with a sunspot which is a magnetic structure visible in the solar photosphere. In this study we explore this aspect of association of Plages with sunspots using the newly digitized Kodaikanal Ca $\scriptsize{\textrm{II}}$ K plage data and the Greenwich sunspot area data. Instead of using the plage index or fractional plage area and their comparison with the sunspot number, we use, to our knowledge for the first time, the individual plage areas and compared it with the sunspot area time series. Our analysis shows that these two structures formed at two different layers are highly correlated with each other on a time scale comparable to the solar cycle. The area and the latitudinal distributions of Plages are also similar to that of the sunspots. Different area thresholdings on the `Butterfly diagram' reveal that Plages with area $\geq$4 arcmin$^2$ are mostly associated with a sunspot in the photosphere. Apart from this, we found that the cyclic properties change when different sized Plages are considered separately. These results may help us to better understand the generation and the evolution of the magnetic structures in different layers of the solar atmosphere.
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association of Plages with sunspots a multi wavelength study using kodaikanal ca scriptsize textrm ii k and greenwich sunspot area data
arXiv: Solar and Stellar Astrophysics, 2016Co-Authors: Sudip Mandal, Subhamoy Chatterjee, Dipankar BanerjeeAbstract:Plages are the magnetically active chromospheric structures prominently visible in Ca $\scriptsize{\textrm{II}}$ K line (3933.67 A). A plage may or may not be associated with a sunspot which is a magnetic structure visible in the solar photosphere. In this study we explore this aspect of association of Plages with sunspots using the newly digitized Kodaikanal Ca $\scriptsize{\textrm{II}}$ K plage data and the Greenwich sunspot area data. Instead of using the plage index or fractional plage area and their comparison with the sunspot number, we use, to our knowledge for the first time, the individual plage areas and compared it with the sunspot area time series. Our analysis shows that these two structures formed at two different layers are highly correlated with each other on a time scale comparable to the solar cycle. The area and the latitudinal distributions of Plages are also similar to that of the sunspots. Different area thresholdings on the `Butterfly diagram' reveal that Plages with area $\geq$4 arcmin$^2$ are mostly associated with a sunspot in the photosphere. Apart from this, we found that the cyclic properties change when different sized Plages are considered separately. These results may help us to better understand the generation and the evolution of the magnetic structures in different layers of the solar atmosphere.