Peter Lundqvist | Stockholm University (original) (raw)
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Papers by Peter Lundqvist
European Southern Observatory Conference and Workshop Proceedings, 1987
American Astronomical Society Meeting Abstracts, Dec 1, 2000
ABSTRACT
International Astronomical Union Circular, Aug 1, 2001
ABSTRACT
Astronomy and Astrophysics, Jan 21, 2011
The astronomer's telegram, Oct 1, 2016
VizieR Online Data Catalog, 2004
ABSTRACT table3 lists the VPFIT parameters (velocity v, Doppler parameter b and column density N)... more ABSTRACT table3 lists the VPFIT parameters (velocity v, Doppler parameter b and column density N) for the components of the observed atomic interstellar lines of Ca II, Ti II, Na I and K I towards SN 2001el and SN 2003hn. In the last column we give the total column density, summed over the individual components. (1 data file).
Astronomy and Astrophysics, Jul 18, 2016
The astrophysical journal, Feb 10, 2017
Monthly Notices of the Royal Astronomical Society, Oct 13, 2017
Monthly Notices of the Royal Astronomical Society, Apr 4, 2017
Monthly Notices of the Royal Astronomical Society, Sep 7, 2015
The Astrophysical Journal, Mar 11, 2005
VizieR Online Data Catalog, 2020
The astronomer's telegram, 2018
arXiv (Cornell University), May 29, 1999
The Astrophysical Journal, May 1, 2023
When discovered, SN 2017egm was the closest (redshift z = 0.03) hydrogen-poor superluminous super... more When discovered, SN 2017egm was the closest (redshift z = 0.03) hydrogen-poor superluminous supernova (SLSN-I) and a rare case that exploded in a massive and metal-rich galaxy. Thus, it has since been extensively observed and studied. We report spectroscopic data showing strong emission at around He i λ10830 and four He i absorption lines in the optical. Consequently, we classify SN 2017egm as a member of an emerging population of helium-rich SLSNe-I (i.e., SLSNe-Ib). We also present our late-time photometric observations. By combining them with archival data, we analyze high-cadence ultraviolet, optical, and near-infrared light curves spanning from early pre-peak (∼−20 days) to late phases (∼+300 days). We obtain its most complete bolometric light curve, in which multiple bumps are identified. None of the previously proposed models can satisfactorily explain all main light-curve features, while multiple interactions between the ejecta and circumstellar material (CSM) may explain the undulating features. The prominent infrared excess with a blackbody luminosity of 107–108 L ⊙ detected in SN 2017egm could originate from the emission of either an echo of a pre-existing dust shell or newly formed dust, offering an additional piece of evidence supporting the ejecta–CSM interaction model. Moreover, our analysis of deep Chandra observations yields the tightest-ever constraint on the X-ray emission of an SLSN-I, amounting to an X-ray-to-optical luminosity ratio ≲10−3 at late phases (∼100–200 days), which could help explore its close environment and central engine.
arXiv (Cornell University), Aug 14, 2023
The use of Type Ia supernovae (SNe Ia) as distance indicators is essential for studying the expan... more The use of Type Ia supernovae (SNe Ia) as distance indicators is essential for studying the expansion history of the Universe and for exploring the nature of dark energy. However, a lack of understanding of the progenitor systems and the empirically derived colour-brightness corrections represent severe limitations for SNe Ia as cosmological probes. In this thesis, we study how dust along the line of sight towards SNe Ia affects the observed light over a wide range of wavelengths; from X-rays to infrared.Unless properly corrected for, the existence of intergalactic dust will introduce a redshift dependent magnitude offset to standard candle sources and bias the cosmological parameter estimates as derived from observations of SNe Ia. We model the optical extinction and X-ray scattering properties of intergalactic dust grains to constrain the intergalactic opacity using a combined analysis of observed quasar colours and measurements of the soft X-ray background. We place upper limits on the extinction AB(z = 1) < 0.10 - 0.25 mag, and the dust density parameter Ωdust < 10−5 − 10−4 (ρgrain/3 g cm−3), for models with RV < 12 − ∞, respectively.Dust in the host galaxies, and dust that may reside in the circumstellar (CS) environment, have important implications for the observed colours of SNe Ia. Using the Hubble Space Telescope and several ground based telescopes, we measure the extinction law, from UV to NIR, for a sample of six nearby SNe Ia. The SNe span a range of E(B − V ) ≈ 0.1 − 1.4 mag and RV ≈ 1.5 − 2.7, showing a diversity of dust extinction parameters. We present mid- and far-infrared (IR) observations for a number of SNe Ia, obtained with the Herschel Space Observatory and Spitzer Space Telescope, addressing CS dust as an explanation for “peculiar” extinction towards some SNe Ia. No excess IR emission is detected, limiting CS dust masses, Mdust < 10−5 solar masses. In particular, the timely appearance of SN 2014J in M82 - the closest SN Ia in several decades - allows for detailed studies, across an unprecedented wavelength range, of its lightcurve and spectral evolution along with the host galaxy and CS environment.
European Southern Observatory Conference and Workshop Proceedings, 1987
American Astronomical Society Meeting Abstracts, Dec 1, 2000
ABSTRACT
International Astronomical Union Circular, Aug 1, 2001
ABSTRACT
Astronomy and Astrophysics, Jan 21, 2011
The astronomer's telegram, Oct 1, 2016
VizieR Online Data Catalog, 2004
ABSTRACT table3 lists the VPFIT parameters (velocity v, Doppler parameter b and column density N)... more ABSTRACT table3 lists the VPFIT parameters (velocity v, Doppler parameter b and column density N) for the components of the observed atomic interstellar lines of Ca II, Ti II, Na I and K I towards SN 2001el and SN 2003hn. In the last column we give the total column density, summed over the individual components. (1 data file).
Astronomy and Astrophysics, Jul 18, 2016
The astrophysical journal, Feb 10, 2017
Monthly Notices of the Royal Astronomical Society, Oct 13, 2017
Monthly Notices of the Royal Astronomical Society, Apr 4, 2017
Monthly Notices of the Royal Astronomical Society, Sep 7, 2015
The Astrophysical Journal, Mar 11, 2005
VizieR Online Data Catalog, 2020
The astronomer's telegram, 2018
arXiv (Cornell University), May 29, 1999
The Astrophysical Journal, May 1, 2023
When discovered, SN 2017egm was the closest (redshift z = 0.03) hydrogen-poor superluminous super... more When discovered, SN 2017egm was the closest (redshift z = 0.03) hydrogen-poor superluminous supernova (SLSN-I) and a rare case that exploded in a massive and metal-rich galaxy. Thus, it has since been extensively observed and studied. We report spectroscopic data showing strong emission at around He i λ10830 and four He i absorption lines in the optical. Consequently, we classify SN 2017egm as a member of an emerging population of helium-rich SLSNe-I (i.e., SLSNe-Ib). We also present our late-time photometric observations. By combining them with archival data, we analyze high-cadence ultraviolet, optical, and near-infrared light curves spanning from early pre-peak (∼−20 days) to late phases (∼+300 days). We obtain its most complete bolometric light curve, in which multiple bumps are identified. None of the previously proposed models can satisfactorily explain all main light-curve features, while multiple interactions between the ejecta and circumstellar material (CSM) may explain the undulating features. The prominent infrared excess with a blackbody luminosity of 107–108 L ⊙ detected in SN 2017egm could originate from the emission of either an echo of a pre-existing dust shell or newly formed dust, offering an additional piece of evidence supporting the ejecta–CSM interaction model. Moreover, our analysis of deep Chandra observations yields the tightest-ever constraint on the X-ray emission of an SLSN-I, amounting to an X-ray-to-optical luminosity ratio ≲10−3 at late phases (∼100–200 days), which could help explore its close environment and central engine.
arXiv (Cornell University), Aug 14, 2023
The use of Type Ia supernovae (SNe Ia) as distance indicators is essential for studying the expan... more The use of Type Ia supernovae (SNe Ia) as distance indicators is essential for studying the expansion history of the Universe and for exploring the nature of dark energy. However, a lack of understanding of the progenitor systems and the empirically derived colour-brightness corrections represent severe limitations for SNe Ia as cosmological probes. In this thesis, we study how dust along the line of sight towards SNe Ia affects the observed light over a wide range of wavelengths; from X-rays to infrared.Unless properly corrected for, the existence of intergalactic dust will introduce a redshift dependent magnitude offset to standard candle sources and bias the cosmological parameter estimates as derived from observations of SNe Ia. We model the optical extinction and X-ray scattering properties of intergalactic dust grains to constrain the intergalactic opacity using a combined analysis of observed quasar colours and measurements of the soft X-ray background. We place upper limits on the extinction AB(z = 1) < 0.10 - 0.25 mag, and the dust density parameter Ωdust < 10−5 − 10−4 (ρgrain/3 g cm−3), for models with RV < 12 − ∞, respectively.Dust in the host galaxies, and dust that may reside in the circumstellar (CS) environment, have important implications for the observed colours of SNe Ia. Using the Hubble Space Telescope and several ground based telescopes, we measure the extinction law, from UV to NIR, for a sample of six nearby SNe Ia. The SNe span a range of E(B − V ) ≈ 0.1 − 1.4 mag and RV ≈ 1.5 − 2.7, showing a diversity of dust extinction parameters. We present mid- and far-infrared (IR) observations for a number of SNe Ia, obtained with the Herschel Space Observatory and Spitzer Space Telescope, addressing CS dust as an explanation for “peculiar” extinction towards some SNe Ia. No excess IR emission is detected, limiting CS dust masses, Mdust < 10−5 solar masses. In particular, the timely appearance of SN 2014J in M82 - the closest SN Ia in several decades - allows for detailed studies, across an unprecedented wavelength range, of its lightcurve and spectral evolution along with the host galaxy and CS environment.