Paleo-environmental sedimentation conditions and organic matter preservation in Mejillones del Su... more Paleo-environmental sedimentation conditions and organic matter preservation in Mejillones del Sur Bay (23º S), Chile.
The Lick AGN Monitoring Project 2011 observing campaign was carried out over the course of 11 wee... more The Lick AGN Monitoring Project 2011 observing campaign was carried out over the course of 11 weeks in Spring 2011. Here we present the first results from this program, a measurement of the broad-line reverberation lag in the Seyfert 1 galaxy Mrk 50. Combining our data with supplemental observations obtained prior to the start of the main observing campaign, our dataset covers a total duration of 4.5 months. During this time, Mrk 50 was highly variable, exhibiting a maximum variability amplitude of a factor of 4 in the U-band continuum and a factor of 2 in the H-beta line. Using standard cross-correlation techniques, we find that H-beta and H-gamma lag the V-band continuum by tau_cen = 10.64(-0.93,+0.82) and 8.43(-1.28,+1.30) days, respectively, while the lag of He II 4686 is unresolved. The H-beta line exhibits a symmetric velocity-resolved reverberation signature with shorter lags in the high-velocity wings than in the line core, consistent with an origin in a broad-line region dominated by orbital motion rather than infall or outflow. Assuming a virial normalization factor of f=5.25, the virial estimate of the black hole mass is (3.2+-0.5)*10^7 solar masses. These observations demonstrate that Mrk 50 is among the most promising nearby active galaxies for detailed investigations of broad-line region structure and dynamics.
The Seyfert 1 galaxy Zw 229-015 is among the brightest active galaxies being monitored by the Kep... more The Seyfert 1 galaxy Zw 229-015 is among the brightest active galaxies being monitored by the Kepler mission. In order to determine the black hole mass in Zw 229-015 from Hβ reverberation mapping, we have carried out nightly observations with the Kast Spectrograph at the Lick 3 m telescope during the dark runs from June through December 2010, obtaining 54 spectroscopic observations in total. We have also obtained nightly V -band imaging with the Katzman Automatic Imaging Telescope at Lick Observatory and with the 0.9 m telescope at the Brigham Young University West Mountain Observatory over the same period. We detect strong variability in the source, which exhibited more than a factor of 2 change in broad Hβ flux. From crosscorrelation measurements, we find that the Hβ light curve has a rest-frame lag of 3.86 +0.69 −0.90 days with respect to the V -band continuum variations. We also measure reverberation lags for Hα and Hγ and find an upper limit to the Hδ lag. Combining the Hβ lag measurement with a broad Hβ width of σ line = 1590 ± 47 km s −1 measured from the root-mean-square variability spectrum, we obtain a virial estimate of M BH = 1.00 +0.19 −0.24 × 10 7 M ⊙ for the black hole in Zw 229-015. As a Kepler target, Zw 229-015 will eventually have one of the highest-quality optical light curves ever measured for any active galaxy, and the black hole mass determined from reverberation mapping will serve as a benchmark for testing relationships between black hole mass and continuum variability characteristics in active galactic nuclei.
The Lick AGN Monitoring Project 2011 observing campaign was carried out over the course of 11 wee... more The Lick AGN Monitoring Project 2011 observing campaign was carried out over the course of 11 weeks in Spring 2011. Here we present the first results from this program, a measurement of the broad-line reverberation lag in the Seyfert 1 galaxy Mrk 50. Combining our data with supplemental observations obtained prior to the start of the main observing campaign, our dataset covers a total duration of 4.5 months. During this time, Mrk 50 was highly variable, exhibiting a maximum variability amplitude of a factor of ∼ 4 in the U-band continuum and a factor of ∼ 2 in the Hβ line. Using standard cross-correlation techniques, we find that Hβ and Hγ lag the V -band continuum by τ cen = 10.64 +0.82 −0.93 and 8.43 +1.30 −1.28 days, respectively, while the lag of He II λ4686 is unresolved. The Hβ line exhibits a symmetric velocity-resolved reverberation signature with shorter lags in the high-velocity wings than in the line core, consistent with an origin in a broad-line region dominated by orbital motion rather than infall or outflow. Assuming a virial normalization factor of f = 5.25, the virial estimate of the black hole mass is (3.2 ± 0.5) × 10 7 M ⊙ . These observations demonstrate that Mrk 50 is among the most promising nearby active galaxies for detailed investigations of broad-line region structure and dynamics.
Ten trace elements (Cr, Zn, Fe, Mn, Cu, Co, Ni, Mo, V and Sr) and sulfur were determined in the s... more Ten trace elements (Cr, Zn, Fe, Mn, Cu, Co, Ni, Mo, V and Sr) and sulfur were determined in the saturate, aromatic and resin fractions of 15 crude oils from Mara (DM) and Mara Oeste (DMO) fields of the Maracaibo Basin, Venezuela. The oils studied are classified as unaltered or altered by biodegradation. In the altered oil, the depletion of
The asphaltenes of the asphalts from the Dead Sea Basin were examined for the occurrence of vanad... more The asphaltenes of the asphalts from the Dead Sea Basin were examined for the occurrence of vanadyl porphyrins. These examinations demonstrate that the asphalts fall into two broad class types: one which exhibits a relatively high vanadyl porphyrins content (>300ppm), and the other characterized with no vanadyl porphyrins (<10ppm). It is concluded that these asphalts belong to two distinct types
Paleo-environmental sedimentation conditions and organic matter preservation in Mejillones del Su... more Paleo-environmental sedimentation conditions and organic matter preservation in Mejillones del Sur Bay (23º S), Chile.
The Lick AGN Monitoring Project 2011 observing campaign was carried out over the course of 11 wee... more The Lick AGN Monitoring Project 2011 observing campaign was carried out over the course of 11 weeks in Spring 2011. Here we present the first results from this program, a measurement of the broad-line reverberation lag in the Seyfert 1 galaxy Mrk 50. Combining our data with supplemental observations obtained prior to the start of the main observing campaign, our dataset covers a total duration of 4.5 months. During this time, Mrk 50 was highly variable, exhibiting a maximum variability amplitude of a factor of 4 in the U-band continuum and a factor of 2 in the H-beta line. Using standard cross-correlation techniques, we find that H-beta and H-gamma lag the V-band continuum by tau_cen = 10.64(-0.93,+0.82) and 8.43(-1.28,+1.30) days, respectively, while the lag of He II 4686 is unresolved. The H-beta line exhibits a symmetric velocity-resolved reverberation signature with shorter lags in the high-velocity wings than in the line core, consistent with an origin in a broad-line region dominated by orbital motion rather than infall or outflow. Assuming a virial normalization factor of f=5.25, the virial estimate of the black hole mass is (3.2+-0.5)*10^7 solar masses. These observations demonstrate that Mrk 50 is among the most promising nearby active galaxies for detailed investigations of broad-line region structure and dynamics.
The Seyfert 1 galaxy Zw 229-015 is among the brightest active galaxies being monitored by the Kep... more The Seyfert 1 galaxy Zw 229-015 is among the brightest active galaxies being monitored by the Kepler mission. In order to determine the black hole mass in Zw 229-015 from Hβ reverberation mapping, we have carried out nightly observations with the Kast Spectrograph at the Lick 3 m telescope during the dark runs from June through December 2010, obtaining 54 spectroscopic observations in total. We have also obtained nightly V -band imaging with the Katzman Automatic Imaging Telescope at Lick Observatory and with the 0.9 m telescope at the Brigham Young University West Mountain Observatory over the same period. We detect strong variability in the source, which exhibited more than a factor of 2 change in broad Hβ flux. From crosscorrelation measurements, we find that the Hβ light curve has a rest-frame lag of 3.86 +0.69 −0.90 days with respect to the V -band continuum variations. We also measure reverberation lags for Hα and Hγ and find an upper limit to the Hδ lag. Combining the Hβ lag measurement with a broad Hβ width of σ line = 1590 ± 47 km s −1 measured from the root-mean-square variability spectrum, we obtain a virial estimate of M BH = 1.00 +0.19 −0.24 × 10 7 M ⊙ for the black hole in Zw 229-015. As a Kepler target, Zw 229-015 will eventually have one of the highest-quality optical light curves ever measured for any active galaxy, and the black hole mass determined from reverberation mapping will serve as a benchmark for testing relationships between black hole mass and continuum variability characteristics in active galactic nuclei.
The Lick AGN Monitoring Project 2011 observing campaign was carried out over the course of 11 wee... more The Lick AGN Monitoring Project 2011 observing campaign was carried out over the course of 11 weeks in Spring 2011. Here we present the first results from this program, a measurement of the broad-line reverberation lag in the Seyfert 1 galaxy Mrk 50. Combining our data with supplemental observations obtained prior to the start of the main observing campaign, our dataset covers a total duration of 4.5 months. During this time, Mrk 50 was highly variable, exhibiting a maximum variability amplitude of a factor of ∼ 4 in the U-band continuum and a factor of ∼ 2 in the Hβ line. Using standard cross-correlation techniques, we find that Hβ and Hγ lag the V -band continuum by τ cen = 10.64 +0.82 −0.93 and 8.43 +1.30 −1.28 days, respectively, while the lag of He II λ4686 is unresolved. The Hβ line exhibits a symmetric velocity-resolved reverberation signature with shorter lags in the high-velocity wings than in the line core, consistent with an origin in a broad-line region dominated by orbital motion rather than infall or outflow. Assuming a virial normalization factor of f = 5.25, the virial estimate of the black hole mass is (3.2 ± 0.5) × 10 7 M ⊙ . These observations demonstrate that Mrk 50 is among the most promising nearby active galaxies for detailed investigations of broad-line region structure and dynamics.
Ten trace elements (Cr, Zn, Fe, Mn, Cu, Co, Ni, Mo, V and Sr) and sulfur were determined in the s... more Ten trace elements (Cr, Zn, Fe, Mn, Cu, Co, Ni, Mo, V and Sr) and sulfur were determined in the saturate, aromatic and resin fractions of 15 crude oils from Mara (DM) and Mara Oeste (DMO) fields of the Maracaibo Basin, Venezuela. The oils studied are classified as unaltered or altered by biodegradation. In the altered oil, the depletion of
The asphaltenes of the asphalts from the Dead Sea Basin were examined for the occurrence of vanad... more The asphaltenes of the asphalts from the Dead Sea Basin were examined for the occurrence of vanadyl porphyrins. These examinations demonstrate that the asphalts fall into two broad class types: one which exhibits a relatively high vanadyl porphyrins content (>300ppm), and the other characterized with no vanadyl porphyrins (<10ppm). It is concluded that these asphalts belong to two distinct types
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Papers by Liliana Lopez