MM WE WERE DOING DESCRIPTIONS THAT MADE THINGS SEPARATE CLASSES IN WHICH CASE I'D ARGUE FOR ELLIPTICAL I THINK MY GOD I'VE JUST GONE MAD WITH THE UNDERLINING HERE YES UM BREAKING THE POWER LAW INDEX I THINK THAT'S PROBABLY A YOU CAN POINT TO IT BUT EQUALLY IT'S NOT A IT'S SOMETHING YOU'VE DERIVED THE PARALLEL INDEX IS SOMETHING YOU DESI DERIVE A BREAK IN A SPECTRUM IS SOMETHING YOU CAN POINT AT SO SO WHAT'S A BREAKING A POWER LAW INDEX I THINK IT'S A FEATURE UM BECAUSE IN THE S SP SPECTRUM IT DOES THAT AND IT DOES THAT SO IT YEAH THAT'S THAT IS WHERE IT BREAKS SO YEAH SLIGHT DEPRESSION OF THE CONTINUUM NEAR THE LYMAN LIMIT I THINK YOU'RE RIGHT THERE AS WELL BUT WE'RE SUPPOSED TO SAY W BUT WE'RE SUPPOSED TO SAY THE DESCRIPTIVE WORDS OF THE FEATURES SO YEAH I IF IT WAS ABSORPTION AT H. ALPHA THAT WOULD ALL BE ONE OR ABSORPTION AT FIVE THOUSAND NANOMETRES WOULD ALL BE ONE ANYWAY YEAH BUT THEY WOULD BE THE SAME THEY'D BOTH BE THE SAME SPECTRAL FEATURE WHEREAS HERE THEY'RE TWO SPECTRAL FEATURES THERE'S A LYMAN LIMIT WHICH YOU COULD SEE AND THEN THERE'S A SLIGHT DEPRESSION NEAR IT BUT IT'S IT'S NEAR RATHER THAN AT IT'S NOT YEAH LET'S MARK THAT THEN OH YOU WANT TO S SPLIT THAT ONE AND DO YOU INTO TWO YEAH YEAH UH I'D AGREE WITH THAT I THINK YEAH IS THAT K. CLEAR OH YEAH OKAY UH-HUH THAT I DIDN'T MARK BECAUSE IT'S THE PHYSICAL PROCESS OF ABSORPTION YES AND YOU'RE RIGHT THERE AS WELL TELL YOU WHO'S MORE AWAKE AT THIS WOULD THERE BE OTHER CASES WHERE YOU WOULD ACTUALLY MARK AN AB ABSORPTION OR YEAH IF IT WAS THERE'S AN ABSORPTION FEATURE OR ABSORPTION TO SEE IT THE SPECTRUM AT THIS WAVE LENGTH BUT WHEN YOU SAY FOR EXAMPLE THE THE QUASAR IS ABSORBED THAT JUST MEANS THE QUASAR IS BEHIND A A BUNCH OF STUFF SO THAT'S DESCRIBING SOMETHING PHYSICALLY RATHER THAN DESCRIBING THE SPECTRUM ITSELF MM-HMM OKAY THANK YOU THERE IS NO STEEP SOFT COMPONENT BUT OUR TWO K. V. I DON'T REMEMBER WHAT WE WERE GONNA DO ABOUT THINGS THAT WEREN'T THERE MM IT'S NOT SOMETHING YOU CAN POINT TO YOU COULD POINT TO IT IF IT WERE THERE YES YOU COULD I TEND TO MISS OUT THINGS IF THEY'RE TOO LONG UM BUT IF IT HAD BEEN THERE UM YOU WOULD'VE YOU WOULD POINT TO IT YEAH YES I THINK YOU'RE RIGHT SHOULD WE GO BACK TO NUMBER FIVE IS THAT THE NEBULA HUH OH YEAH YEAH WHAT WERE WE SAYING ABOUT NEBULA SOURCE TYPES NO NEBULA COUNTS DOESN'T IT I THINK IT DOES WE WEREN'T MATCHING A H. TWO REGIONS BECAUSE IT WAS A REGION I THINK WAS THE ARGUMENT FOR THAT LINE AGAIN LINE IN RATIOS BUT I REMEMBER WE WEREN'T GONNA MARK LINE RATIOS BUT WE WERE GOING TO MARK 'CAU WE'RE HERE WHERE YOU'VE GOT EQUIVALENT WIDTH OF H. BETA ORBITED BUT RATIO IS DIFFERENT I GUESS MM IT ISN'T IT IT'S IT'S NOT TALKING ABOUT SPECIFIC LINES A LINE RATIO IS A THING YEAH BECAUSE YOU HAVEN'T ACTUALLY LISTED EXPLICITLY UM THAT YOU'RE NOT GOING TO INCLUDE IT RIGHT DON'T INCLUDE SO OH I SEE WHAT YOU MEAN UM DON'T IT IN INCLUDE THE DERIVED PROPERTY NO YEAH IT SHOULDN'T BE IN OKAY WHOOP NO OH I SEE WHAT YOU'RE DOING YOU'RE CIRCLING THE ONE WE LIKE RIGHT DAMPED LYMAN ALPHA ABSORBERS I THINK THAT'S A SPECTRAL FEATURE EVEN THOUGH IT'S YOU WOULDN'T MARK THE SOURCE TYPE OH SORRY UM YEP YES BECAUSE WE DON'T WANT IT UNDERLINED IT SHOULDN'T BE HIGHLIGHTED SO YEAH M I SEE B MM-HMM BUT IT'S ALSO A I I IF WE HAVE BUT TH BUT YOU ALSO ABSORB THEM BY Y YOU OBSERVE THEM BY THEIR SPECTRAL FEATURE WHAT WERE WE DOING FOR THINGS BROAD ABSORPTION LINE QUASAR FOR EXAMPLE WE WERE MARKING THE BROAD ABSORPTION LINE AS WELL AS BROAD ABSORPTION LINE QUASAR YE IF IT'S DEFINED BY A SPECTRAL FEATURE WE SHOULD MARK IT BUT UH YOU WOULDN'T BE ABLE TO POINT SOMETHING IN A SPECTRUM AND SAY THAT'S A DAMPED LYMAN ALPHA ABSORBER UNLESS YOU'D YEAH YEAH YOU COULD DO BUT WE WOULDN'T SAY ABSORBERS WERE A TYPE OF SOURCE UM NOT A BIS SPECIFIC TYPE OF SOURCE BUT I THINK STILL THE THE SPECTRAL FEATURE GE COUNTS EVEN THOUGH IT'S M A MODIFIER OF SOMETHING OKAY I'M NOT CERTAIN ABOUT THAT BUT I WHAT DO YOU RECKON BOB UM WELL I MEAN YOU COULD LOOK AT THIS THIS SPECTRUM AND SPOT THAT UM TH L LYMAN ALPHA HAS BEEN DAMPED BUT D DON'T WITH DAMPED LYMAN ALPHA OBSERVERS YOU THEM A VARIETY OF PLACES ALONG THE LINE OF SIGHT SO YOU HAVE TO KNOW NO THAT'S TRUE HOW DOES IT WORK I DON'T KNOW WHAT WHICH DOESN'T HELP YOU CAN SEE THESE THINGS AND BUT YOU WOULDN'T BE ABLE TO POINT AT ONE OF THEM AND SAY AH THAT'S A DAMP YEAH THEY'RE GONNA BE AT DIFFERENT RED SHIFTS BUT THAT DOESN'T MEAN THAT IT'S YOU COULD STILL SAY THAT'S DAMPED LYMAN ALPHA AND THAT'S DAMPED LYMAN ALPHA I DON'T KNOW HOW THEY DO TH THAT BUT BUT YOU'RE GUESSING IN A WAY THOUGH AREN'T YOU SO BUT ISN'T THAT J ALWAYS THE CASE WITH SOMETHING THAT'S NOT PARTICULARLY WELL NO BUT YOU SEE THEM IN ALL SORTS OF DIFFERENT RED RED SHIFTS IT'S LIKE THE THE LYMAN ALPHA FOREST SORT OF AND I'M NOT CERTAIN I WOULD I WOULD MARK THAT MM THAT'S A THAT'S A TRICKY ONE CERTAIN CERTAINLY WOULD WE MARK IT UM NO I WOULDN'T BECAUSE IT'S THEY'RE PHYSICAL THINGS NOT SPECTRAL FEATURES YOU CAN'T POINT AT SOMETHING ON A SPECTRUM AND SAY THAT'S DEFINITELY A D DAMPED LYMAN ALPHA SOME I G AND I GUESS IT'S BECAUSE THEY'RE MODIFIERS OF THIS SOURCE TYPE AND WE WOULDN'T MARK THAT SOURCE TYPE BUT WE INCLUDE MODIFIERS OF SOURCE TYPES WE WOULD MARK WE'RE NOT MARKING ABSORBERS BUT IF IT WAS A DAMPED LYMAN ALPHA QUASAR THEN WE WOULD MARK QUASAR AND WE WOULD MARK DAMPED LYMAN ALPHA IF IT WAS BROAD ABSORPTION LINE QUASAR WE'D MARK IT YEAH SO IT'S JUST I GUESS WHETHER DAMPED LYMAN ALPHA IS A SPECTRAL FEATURE IN ITSELF WHICH I WOULD PROBABLY SAY IT WAS BUT THEN I'VE NEVER LOOKED AT I ONE I OKAY I MEAN IS A CH MM-HMM CHANGE IN THE S SPECTRUM OF IT DOESN'T HAVE TO BE SOMETHING THAT'S SPECIFIC I GUESS Y YOU KNOW WE WE SAY A UH BIG BLUE BUMP OR A SOFT OR A CONTINUUM AND WE INCLUDE THOSE BUT WE WEREN'T GOING TO INCLUDE S DESCRIPTIONS OF SPECTRAL FEATURES THAT WERE BASED ON FITTING WERE WE UH IS THAT RIGHT HAVE WE WELL NO WE INCLUDED P STEEP SOFT COMPONENT SORRY AND HERE WE INCLUDED BREAKING THE POWER LAW BECAUSE OF THE BREAK STEEP SOFT COMPONENT YEAH BREAKING THE POWER LAW IS SOMETHING I'M NOT CERTAIN OF STEEP SOFT COMPONENT IS SOMETHING YOU CAN POINT AT IN A SPECTRUM AND SAY THERE IT IS YEAH